Philosophy of Science and the Theory of Natural Selection John Losee Lafayette College
ABSTRACT: Toulmin, Hull, Campbell, and Popper have defended an "Evolutionary-Analogy" view of scientific evaluative practice. In this view, competing concepts, theories and methods of inquiry engage in a competitive struggle from which the "best adapted" emerge victorious. Whether applications of this analogy contribute to our understanding of science depends on the importance accorded the disanalogies between natural selection theory and scientific inquiry. Michael Ruse has suggested instead an "Evolutionary-Origins" view of scientific evaluative practices in which scientific inquiry is directed by application of epigenetic rules that have become encoded in homo sapiens in the course of evolutionary adaptation. Among these rules are "formulative theories that are internally consistent," "seek severe tests of theories," (Popper) and "achieve a consilience of inductions" (Whewell). As a descriptive theory of science, the "Evolutionary-Origins" view is prima facie inconsistent with evidence that human beings often make decisions that violate the "genetically-hard-wired rules." As a normative-prescriptive philosophy of science, the "Evolutionary-Origins" view is limited by the fact that in biological evolution, adaptation to present pressures may be achieved at the expense of a loss of adaptability (the capacity to respond creatively to future changes in environmental conditions). In the 1980s, the hitherto-dominant normative-prescriptive conception of philosophy of science became the subject of a debate which continues to the present time. Some philosophers of science suggested that the proper aim of the discipline is the description of scientific evaluative practice.
There is a modest version and a robust version of descriptive philosophy of science. The aim of the modest version is the historical reconstruction of actual evaluative practice. Given that scientists preferred one theory (explanation, research strategy...) to a second, the modest descriptivist seeks to uncover the evaluative standards whose application led to this preference. For instance, the modest descriptivist may seek to uncover the standards implicit within such evaluative decisions as Aristotle's rejection of pangenesis, Newton's rejection of Cartesian Vortex Theory, or Einstein's insistence that the Copenhagen Interpretation of quantum mechanics is incomplete. Pursuit of a modest descriptive philosophy of science may require a certain amount of detective work, particularly for episodes in which the pronouncements of scientists and their actual practice do not coincide.
The conclusions reached by modest descriptive philosophy of science are subject to appraisal by reference to standards applicable to historical reconstruction in general. There is no distinctively philosophical task of appraisal. The modest descriptivist is a historian with a particular interest in evaluative practice.
The robust version of descriptive philosophy of science derives from, or superimposes upon, the conclusions of modest descriptivism, a theory about evaluative practice. The theory is put forward as a contribution to our understanding of science. It purports to explain why science is as it is. A robust descriptive philosophy of science typically includes the claim that scientific evaluative practices exhibit
certain patterns or conform to certain principles. Of course, not every historical instance will exhibit a pattern exactly or conform precisely to the requirements of a principle. But a successful robust descriptive theory must help us to understand at least some important episodes from the history of science.
A number of philosophers of science have sought to account for the growth of science by reference to the Theory of Organic Evolution. Michael Ruse has observed that "evolutionary philosophies of science" may be subdivided into two types. (1)
1) The "Evolutionary-Analogy" View develops an analogy between the growth of science and the operation of natural selection upon a pool of variants subject to environmental pressures. On this view, competing concepts, theories and methods of inquiry engage in a competitive struggle from which the "best adapted" emerge victorious.
2) The "Evolutionary-Origins" View attributes the growth of science to the application of epigenetic rules that have proved adaptive within the course of evolutionary history. On this view, science develops as it does because certain methodological rules and evaluative principles have become encoded in our genes. Acting on these rules and principles presumably proved adaptive for our proto-human ancestors.
The "Evolutionary-Analogy" View and the "Evolutionary-Origins" View are, in the first instance, robust descriptive philosophies of science. In addition, some evolutionary theorists have drawn normative-prescriptive recommendations from their theories about scientific progress.
The Evolutionary-Analogy View
Stephen Toulmin, David Hull, Donald Campbell and Karl Popper have developed versions of the Evolutionary-Analogy View. Toulmin maintained that the development of scientific concepts is an evolutionary process in which the fittest conceptual variants survive. (2) In a period of "Kuhnian Revolutionary Science", for instance, the victorious "paradigm" (set of concepts) is the one that best resolves the "anomalies" (disciplinary pressures) that gave rise to the adaptive crisis.
Toulmin held, moreover, that the identity-through-change of a scientific discipline is analogous to the identity-through-change of a biological species. Since we believe that we understand the interrelationship of the concepts 'variant', 'environmental pressure', 'adaptation' and 'fitness' within the theory of organic evolution, successful analogical extension of this interrelationship to the history of scientific evaluative practice presumably conveys understanding of "how science works".
David Hull sought to show that organic evolution and conceptual change are specific instances of a "General Theory of Selection Processes". (3) The General Theory specifies a mechanism by which entities pass on structure over time. The mechanism involves an interrelation among "interactors" and "replicators". Interactors compete with one another in response to environmental pressures. The resultant competitive differential adaptation of interactors causes differential success rates among replicators.
Replicators are entities which give rise to copies of themselves. In the organic realm, "replication occurs primarily at the level of the genetic material". (4) Interactors are entities subject to competition within some specific environment. In the organic realm, "interactors" include not only living organisms, but also genes, chromosomes, cells and kinship groups. (5)
Within the history of science, replicators are concepts and beliefs, and interactors are individual scientists and individual research groups. "Concept-replicators" are individual entities, but they exist in various contexts of interrelatedness. Beliefs also are individual entities, and include commitments to methodological principles and standards of appraisal.
Hull maintained that the history of science, like the history of organic forms, is the result of selective pressure operating upon a set of variants. The history of science is a history of "lineages", theories that change over time while retaining self-identity. Theories, like species, are entities determined by phylogeny, and not by possession of a common structure or set of properties. What counts is descent and not sameness of content.
Hull noted that, on a phylogenetic understanding of theory-life, "unappreciated precursors do not count." (6) Thus, Patrick Matthew's unnoticed formulation of the principle of natural selection (1831) is not part of the lineage of natural-selection theory. He noted also that a "phylogenetic" reconstruction of Darwinian Evolutionary Theory reveals a tree of descent whose branches include "Darwin's Darwinism, late nineteenth-century Darwinism, neo-Darwinian Darwinism, the new synthesis Darwinism, and so on". (7)
Hull's descriptive philosophy of science is robust. He maintained that we may increase our understanding of evaluative practice within science by reference to the General Theory of Selection Processes. Indeed, he claimed that otherwise puzzling aspects of evaluative practice are readily understood when viewed from the standpoint of the General Theory of Selection Processes.
One such puzzle is the success of science in policing the activities of its members. (8) The great majority of professional organizations are ineffective at imposing discipline upon their errant members. Science is a striking exception to the general rule. On Hull's model, an individual scientist is an interactor subject to the pressure of selection. Her "fitness" is established by publishing results that subsequently are acknowledged and utilized by other scientists. It is not in the long-term self-interest of a scientist to falsify or fabricate data, or to distort the conclusions reached by other scientists. Consequently, scientists collectively are quick to condemn and punish those occasional miscreants who undermine the process by which lineages are created.
A second puzzle is the vehemence of priority disputes among scientists. If the goal of science is the formulation of increasingly more powerful theories, what does it matter who receives credit for them? On the General Theory of Selection Processes it matters greatly. Theories are phylogenetic entitities. An interactor's fitness is measured by her contribution to such lineages. Any challenge to an interactor's role in the creation of a lineage is a serious threat indeed. Given Hull's Evolutionary Model, it is not surprising that priority disputes often are heated controversies.
Unfortunately for the Evolutionary-Analogy Program, there are important disanalogies between organic evolution and the growth of science. L. J. Cohen pointed out two such disanalogies.
In the first place, the process by which variants are produced within a breeding population takes place independently of the process by which the "better adapted" individuals succeed in the struggle to survive and reproduce. Mutation is a spontaneous, random process. As Cohen put it
the gamete has no clairvoyant capacity to mutate preferentially in directions preadapted to the novel ecological demands which the resulting organisms are going to encounter at some later time. (9)
The situation is otherwise in science. Variant scientific concepts, methodological rules and evaluative standards are consciously created in order to overcome recognized deficiencies in older concepts, rules and standards. Thus there is an important relationship between the formation of scientific concepts and the subsequent fortunes of the theories within which they occur. "Variation" and "selection" are not uncoupled processes within science.
In the second place, biological species are not analogues of scientific disciplines. A biological species is a population of similar individuals each of which is a representative of that species. The same is not the case for a scientific discipline. A scientific discipline includes concepts, invariant and/or statistical relations among concepts, theories about underlying mechanisms, procedural rules and evaluative standards. These diverse ingredients are interrelated in complex ways. Even if we restrict attention to scientific concepts, it is clear that a concept such as 'force' does not instantiate physics in the way that 'Cigar' instantiates the species Equus.
Cohen emphasized that the identity-through-change of a biological species is markedly dissimilar to the identity-through-change of a scientific discipline. A biological species retains its identity provided that a set of individuals with similar characteristics at time t2 resembles in relevant respects another set of individuals with similar characteristics at time t1. But the identity-through-change of a scientific discipline is not of this type. In order to solve conceptual problems within a discipline we need a set of interrelated concepts, not a population of concepts with similar characteristics. Hence changes within a discipline involve a restructuring of an 'evolving' concept's relations to other concepts and not just a replacement of concepts similar to c1 by concepts similar to c2.
The adequacy of an Evolutionary-Analogy theory of science depends on the importance of the above-mentioned disanalogies. Cohen maintained that the independence of variation-generation and selection is an essential feature of the theory of natural selection. He concluded that the analogy to the growth of science fails. Toulmin and Hull, by contrast, conceded that this disanalogy exists, but insisted that the Evolutionary Analogy nevertheless provides a useful theory of science.
Donald Campbell sought to reinstate the evolutionary analogy by shifting attention from "random mutations" to "blind trials". He acknowledged that scientific beliefs, unlike biological variants, are not produced randomly. The scientist has in mind a problem to be solved and a history of prior attempts to find a solution. However, if scientific progress results from the selective retention of blind trials, then the core of the evolutionary analogy may be retained. Every random trial is a blind trial, but a trial may be blind without being random.
In Campbell's usage, a "blind trial" is a trial that satisfies three conditions: 1) the trial is independent of environmental conditions; 2) a successful trial is no more likely to occur at one point in a series of trials than at any other point in the series, and; 3) no trial in a sequence of trials is put forward as a "correction" of a prior trial. Campbell claimed that
a blind-variation-and-selective-retention process is fundamental to all inductive achievements, to all genuine increases in knowledge, to all increases in fit of system to environment. (10)
Campbell thus maintained that the goal-directed decisions of scientists to entertain specific hypotheses are "blind" forays into the unknown, and that those hypotheses that prove "nonadaptive" under testing are eliminated.
The "Selective-Retention-of-Blind-Variants" View is a program for further research. In order for Campbell's program to succeed as a robust descriptive philosophy of science, two conditions must be fulfilled. The first condition is that the Evolutionary Analogy--amended to require selective retention of "blind" variants--must fit important episodes from the history of science. The second condition is that the "fit" has explanatory force.
Kepler's work on the orbit of Mars is a promising candidate for Campbellian reconstruction. Kepler hypothesized a number of ovoid orbits for Mars ("blind trials") before hitting upon an ellipse. The "blindtrials" picture also may be superimposed upon various programs to "save the appearances". The list of such programs includes Babylonian astronomy (the use of linear zigzag functions to calculate the day on which the next new moon appears), Ptolemy's mathematical models for calculating the zodiacal positions of the planets, the nineteenth-century algebraic chemistrys of Benjamin Brodie and Josiah Cooke, and contemporary econometric modelling of macroeconomic forces.
The modified Evolutionary Analogy is less promising as an account of theories about underlying mechanisms. It remains to be shown that Descartes' Vortex Theory, the Kinetic Theory of Gases, Molecular-Orbital Theory and Plate Tectonics Theory are results of the selective retention of blind trials.
Ron Amundson has insisted that the adequacy of "selection explanations" depends on the degree to which certain "central conditions" are met. These central conditions place restrictions on variation and sorting. Variations must be spontaneous, abundant and heritable modifications that are "nondirected with respect to the environmental needs of the organism". (11) And given a pool of such variants, there must be a
preferential persistence of those variations which happen to be suited to the environmental needs of the organism or species- and (most importantly) this sorting mechanism is itself nonpurposive. (12)
Amundson maintained that the above conditions are necessary conditions of explanatory success for analogical applications of the theory of Natural Selection. He noted that challenges to proposed selection explanations often take the form of a denial that the requisite central conditions are met.
Campbell's "blind-variation-and-selective-retention" theory of scientific change would appear to be subject to two principal challenges. In the first place, the generation of variant hypotheses is neither random nor blind. Rather, hypotheses are put forward in response to recognized inadequacies within the scientific environment. In the second place, the sorting process that results in a decision to reject a high-level hypothesis involves judgments about background knowledge, auxiliary assumptions, experimental procedures, and sometimes even metaphysical principles. Amundson declared that
the process of rejecting a 'falsified' hypothesis is often more like the literary critic's negative assessment of a poem than like the cold wind's freezing of the baldest polar bear. (13)
Campbell sought to blunt this type of criticism by acknowledging the existence of "shortcuts" for the blind-variations-and-selection-process. The formulation of hypotheses designed to address perceived deficiencies within a scientific domain may serve as a shortcut for the method of blind trials. Campbell insisted that such shortcuts themselves are an inductive achievement. He declared that we have acquired a
wisdom about the environment achieved originally by blind variation and selective retention. (14)
Purposefully generated (nonblind) hypotheses may be part of a "phylogenetic lineage" the earlier members of which were generated by the blind-variation-and-selective-retention process.
Campbell's introduction of "shortcuts" raises anew the question about the explanatory force of his Modified Evolutionary Analogy. Does it have explanatory force to argue that scientists entertain goal-directed hypotheses today because at sometime in the past our ancestors engaged in blind trials (upon which selection operated)?
Karl Popper endorsed Campbell's version of the Evolutionary Analogy. He held that the conjectures of scientists are analogous to variations and that refutations are analogous to the selective retention of variants. On this view, the "phylogeny" of science is the lineage of theories that survives the rigors of severe testing.
Popper's opposition to inductivism is well known. He repeatedly insisted that there can be no successful algorithm for theory-formation. Popper likened the position of the theorist to the
situation of a blind man who searches in a dark room for a black hat which is--perhaps--not there. (15)
The theorist, like the blind man, proceeds by trial-and-error, coming to learn where the hat is not, without ever reaching a certainty immune from rejection in the force of further experience.
Popper is correct to emphasize the role of creative imagination in the formulation of scientific hypotheses. The problem-situation does not dictate a solution to the theorist. However, neither are hypotheses formulated independently of the problem-situation. Popper's "black-hat image" is quite misleading. Scientific conjectures are "blind" only in the sense that the outcome of subsequent testing is unknown. They are not "blind" in Campbell's sense of being "independent of the environmental conditions of the occasion of their occurrence".
There is a further difficulty in Popper's particular use of an evolutionary analogy. Popper insisted that scientists ought formulate bold, content-increasing conjectures that run a high risk of falsification. But the Darwinian picture of descent-with-modification is a gradual accretion of small adaptations. Popper claimed explanatory value for an "Evolutionary Analogy" that includes pious references to "Darwinian Theory". But he also introduced "Lamarckian" emphases and "Saltation" effects that are inconsistent with that theory.
Of course, there have been disputes over the specific content of Darwinian Theory. However, if Amundson's "central conditions" express the core of this theory, Michael Ruse is correct to conclude that
Popper has been no more successful than others in making traditional evolutionary epistemology plausible. The growth of science is not genuinely Darwinian. (16)
The Evolutionary-Origins View
The Evolutionary-Origins View, like the Evolutionary-Analogy View, may be defended as a purely descriptive theory about science. The Evolutionary-Analogy View is that there is competition leading to differential reproductive success within both organic evolution and science. The Evolutionary-Origins View is that scientific inquiry is directed by the application of epigenetic rules that have become encoded in homo sapiens in the course of evolutionary adaptation. We have certain capacities and dispositions because it was advantageous for our ancestors to have them.
Michael Ruse called attention to several epigenetic rules that appear to inform human evolution: 1) the partitioning of the (continuous) spectrum into discrete colors, a partitioning that takes place in diverse human cultures, presumably because it confers adaptive advantage in the struggle for existence; 2) the "deep structure" of language uncovered by Chomsky and others, and; 3) the prohibition of incest. Ruse suggested that there exist additional epigenetic rules that govern the creation of science: 1) formulate theories that are internally consistent; 2) seek "severe tests" of theories (Popper); 3) develop theories that are "consilient" (Whewell), and; 4) utilize the principles of logic and mathematics in the formulation and evaluation of theories. (17)
Critics of the Evolutionary-Origins View have pointed out that there is evidence that human beings often make decisions that are inconsistent with these supposedly "genetically-hard-wired" rules. Human subjects affirm the consequent with impunity, succumb to the "gambler's fallacy", and erroneously conclude that the probability of (A & B) is higher than the probability of A alone. Ruse acknowledged that this is evidence against the Evolutionary-Origins View, but insisted that it is
better surely to suppose that much of the time we do not think particularly carefully or logically simply because it is not really necessary to do so, but when pressed we can do so and for very good reasons, namely, that those who could not tended not to survive and reproduce. (18)
This is unconvincing. If certain dispositions are acquired in the evolutionary process because of their adaptive value, then these dispositions ought be uniformly actualized. Ruse is forced to subdivide human actions into those that conform to the epigenetic rules (performed by scientists) and those that do not conform to those rules (performed by nonscientists in cases where it is "not really necessary" to conform). Ruse does not argue that those who fail to apply the epigenetic rules are likely to succumb to evolutionary pressures. Instead he introduces the ad hoc hypothesis that nonconformity occurs in cases in which conformity is not necessary. It is debatable whether such a move is consistent with the empirical method required by the position of evolutionary naturalism. (19)
Normative-prescriptive content may be added to the Evolutionary-Origins View by endorsing the move from
(1) The application of methodological rule R and evaluative standard S were adaptive responses to former ecological pressures P.
(2) R and S ought be applied by scientists today.
Ruse usually resisted the temptation to make this move. However, he sometimes teased the reader with suggestive adaptive scenarios. For example, he contrasted the responses of two hominids to evidence of the presence of tigers. Hominid #1 takes the existence of feathers, blood, paw marks in the mud, and growls from the bushes to establish a consilience of inductions, and flees. Hominid #2 views the same evidence but fails to see the importance of consilience. Ruse then asked "which of these two hominids was your ancestor?" (20) Ruse has led the reader to the point where it is natural to conclude, not only that the disposition to apply a standard of consilience has had adaptive value, but also that this standard ought be applied within science today.
However, Ruse did not issue explicit normative-prescriptive claims on behalf of epigenetic rules. (21) (22) Instead, he compared epigenetic rules to David Hume's "dispositions". Hume had observed that we organize our lives by reading "necessary connections" into Nature. We act on the expectation that correlations experienced in the past will continue to hold in the future. Ruse accepted Hume's account of the dispositions involved in our commerce with the world and appended to the Humean account a theory about the origin of these dispositions.
Hume denied that a rational justification can be provided for our expectations of regularity. Past uniformity does not entail the future continuation of that uniformity. Ruse accepted this Humean claim as well. He suggested that the only "justification" for implementing epigenetic rules is that these rules did arise during the course of human evolution. Ruse acknowledged that to provide a theory about the origin of a rule is to fall short of providing a justification for continuing to implement the rule.
There is a further difficulty for normative-prescriptive versions of evolutionary naturalism. In biological evolution "fitness" is a balance between a successful adaptation to present environmental conditions and the retention of the capacity to respond creatively to future changes in those conditions. In a particular case, successful adaptation may be achieved at the expense of a loss of adaptability. That this has occurred becomes evident only with the passage of time.
The normative-prescriptivist evolutionary naturalist stipulates that a particular evaluative decision is correct provided that it promotes "fitness" in the long run. But how can one know at the time a decision is made that it will do so? One may appeal to the fact that similar decisions in the past have proved to have survival value. However, it always is possible that the ecologically unique present situation requires a different response.
The most adequate appraisals are those rendered long after the fact. Survival is the best indicator of fitness. It is survival that establishes a continuing retention of adaptive capacity in the face of changing conditions. Judgments about contemporary evaluative options are much less secure.
The perceptive normative theorist will accept this limitation on prescriptive adequacy. She will acknowledge the possibihity that what appears at the time to be a "fit" evaluative response may turn out subsequently not to be such. But this need not be a recipe for scepticism. It is no more reasonable to expect certainty in the philosophy of science than it is to expect certainty in science. Notes
(1) Michael Ruse, Taking Darwin Seriously (Oxford: Blackwell, 1986), 29-66;149-68.
(2) Stephen Toulmin, "Rationality and Scientific Discovery: PSA 1972" in Boston Studies in the Philosophy of Science, ed. by K. Schaffner and R. S. Cohen (Dordrecht: Reidel, 1974), Human Understanding, Vol. 1 (Oxford: Clarendon Press, 1972), 133-144.
(3) David Hull, Science as a Process (Chicago: University of Chicago Press, 1988), 409; Metaphysics of Evolution (Albany: SUNY Press, 1989), 96.
(4) Hull, "Conceptual Evolution and the Eye of the Octopus", in The Metaphysics of Evolution, 221.
(5) Ibid., 221.
(6) Ibid., 233.
(7) Ibid., 234-7
(8) Hull, Science as a Process, 301-19.
(9) L. Jonathan Cohen, "Is the Progress of Science Evolutionary?" Brit. J. Phil. Sci. 24 (1973), 47.
(10) Donald T. Campbell, "Blind Variation and Selective Retention in Creative Thought as in Other Knowledge Processes", Psych. Rev. 67 (1960) 380. Reprinted in Evolutionary Epistemology, Rationality, and the Sociology of Knowledge, ed. G. Radnitzky and W. W. Bartley III (LaSalle: Open Court, 1987) 91.
(11) Ron Amundson, "The Trials and Tribulations of Selectionist Explanations" in Issues in Evolutionary Epistemology, ed. K. Hahlweg and C. A. Hooker (Albany: SUNY Press, 1989), 417.
(12) Ibid., 417.
(13) Ibid., 428.
(14) Campbell, "Blind Variation and Selective Retention...", 91.
(15) Karl Popper, "Replies to My Critics", in The Philosophy of Karl Popper, ed. P. A. Schilpp (LaSalle: Open Court, 1974). 1061.
(16) Michael Ruse, Taking Darwin Seriously, 65.
(17) Ruse, Evolutionary Naturalism, 157-65; Taking Darwin Seriously, 149-60.
(19) Karl Popper insisted that a pattern of repeated evasions of prima facie falsifying evidence establishes that a methodology is nonempirical. He conceded, however, that disagreements will arise about how extensive evasive attempts must be before a methodology is thus disqualified.
(20) Ruse, Taking Darwin Seriously, 163.
(21) Larry Laudan, "Progress or Rationality? The Prospects for a Normative Naturalism", Amer. Phil. Quart. 24 (1987), 25
(22) Larry Laudan has displayed no such reticence. He injected normative contact into his version of naturalism by endorsing a meta-methodological principle that stipulates that one ought continue to apply those rules that have proved most effective in the past. Disponible en: http://www.bu.edu/wcp/Papers/Scie/ScieLose.htm
Epistemological Positions in the Light of Truth Approximation
Theo A. F. Kuipers (1) University of Groningen, Groningen, Netherlands T.A.F.Kuipers@philos.rug.nl
ABSTRACT: I discuss in a systematic order the most important epistemological positions in the instrumentalism-realism debate, viz., instrumentalism, constructive empiricism, referential realism, and theory realism. My conclusions are as follows. There are good reasons for the instrumentalist to become a constructive empiricist. In turn, the constructive empiricist is forced to become a referential realist in order to give deeper explanations of success differences. Consequently, there are further good reasons for the referential realist to become a theory realist. The nature of proper theories, that is, theories using theoretical terms, or rather the attitude one should have towards them is the subject of the ongoing realism-instrumentalism debate. We will sketch the most important epistemological positions in this debate. They will be ordered according to their answers to a number of successive leading questions, where every next question presupposes an affirmative answer to the foregoing one. Besides including the answer to questions concerning truth, we will also include the most plausible answer to questions concerning truth approximation. The survey is restricted to the natural sciences and hence to the natural world. It should be stressed that several complications arise if one wants to take the social and cultural world into account. However, the present survey may well function as a point of departure for discussing epistemological positions in the social sciences and the humanities. The survey will primarily be presented in terms of the two-level distinction between observational laws and proper theories, and hence of the short-term dynamics to which that distinction gives rise. That is, proper theories are evaluated and compared in terms of the observational laws they are able to explain and predict. From time to time we will also take the long-term dynamics into account generated by the transformation of proper theories into observation theories and giving rise to a multi-level distinction according to which proper theories may not only explain or predict a lower level observational law, but also be presupposed by a higher level one. Finally, we will talk about two versions of the natural world, the one called the actual world, that is, the natural world of the past, the present and the future, the other called the real world, that is, the natural world in the sense of all conceivable possibilities that are physically possible. We will also call these versions of the natural world the actual (or instantial) and the modal version, respectively. The actual world is of course in some sense part of the real world. The two versions will lead to two versions of each position, that is, the instantial version, merely pertaining to the actual world, and the modal version, which also pertains to the real world.
At the end we will briefly indicate the implications of the results of the study of empirical progress and truth approximation in Structures in Science (manuscript) for the way epistemological positions are related. This will be elaborated in the presentation. Taking the variety of (versions of) positions seriously implies that the notions of 'true' and 'false' are assumed to have adapted specifications. The same holds for the notion of 'the truth', but it should be stressed in advance that it will always be specified in a domain-and-vocabulary relative way. Hence, no language independent metaphysical notion of 'The Truth' is assumed.
The first question really is not an epistemological question, but a preliminary ontological question.
Question 1: Does a natural world that is independent of human beings exist?
The question of whether there is a human-independent natural world is to some extent ambiguous. If one thinks in terms of a conceptualized natural world, that is, a world that in some way or other brings one or more conceptualizations with it, then one has to assume either a kind of essences underlying the natural world, or one has to assume a non-human designer of the natural world, or some human intervention. We take the question in the other sense, that is, does a non-conceptualized natural world independent of human beings exist? If one answers this question negatively one takes the position of (straightforward) ontological idealism. If one answers it positively we will speak of ontological realism. It is certainly questionable (Rescher 1992) whether so-called idealists, like Berkeley, really subscribed to ontological idealism. However this may be, and this is our main argument, it is highly implausible and not taken seriously by natural scientists. The positive answer may be plausible in the instantial version, it is not evident in the modal version. To speak meaningfully about physical possibilities seems to require at least some conceptualization. However, in the same way, to say something specifically about the actual world presupposes some conceptualization. Hence, as far as the role of conceptualizations is concerned, it can be argued that if one believes in an unconceptualized actual world, which can be conceptualized in different ways, one may equally well believe in an unconceptualized real world, which can be conceptualized in at least as many ways. To be precise, there are more, because to conceptualize the real world it is plausible to take also dispositions into account which do not seem to be of any use in characterizing the actual world. Apart from the comparable (epistemological!) role of conceptualizations, it is clear that modal ontological realism makes a stronger ontological claim than instantial ontological realism. In the following, we leave the choice between them open.
The second question is really epistemological.
Question 2: Can we claim to possess true claims to knowledge about the natural world?
Again it is important to first eliminate some ambiguities in this question. A positive answer to this question does not presuppose that true claims can be known to be true with certainty in some fundamental sense, nor that they can be verified or can be recognized as true or can be obtained in some other way. A positive answer evidently does not presuppose that the true claims the question refers to do not depend on a conceptualization, for the formulation of claims requires a vocabulary. What is intended is only that the claim that we can have good reasons for assuming that certain claims, by definition phrased in a certain vocabulary, about the natural world are true in an objective sense, whereas others are false. The negative answer amounts to the position of epistemological relativism, the positive answer may be called epistemological realism, with an instantial and a modal version, depending on whether all of these claims are just claims about the actual world or some about the real world. As with the position of ontological idealism, the position of epistemological relativism is hard to take seriously in some straightforward sense, despite the fact that it seems to be fashionable in certain, so-called postmodern, circles.
The third question brings us to the heart of the distinction between observational and theoretical terms. Assuming a certain definition of observability and hence of the border between observational and theoretical terms, the following question arises:
Question 3: Can we claim to possess true claims to knowledge about the natural world beyond what is observable?
In other words, the third question is whether more than observational knowledge, that is knowledge in observational terms, is possible? A negative answer only makes sense of course if the notion of observability is relatively fixed. Our human observation possibilities might be extended, or just change, due to some evolutionary or artificial change of our physiological abilities. Moreover, they might be extended by accepting some observational laws, that enable the definition of new concepts. However, in case of the negative answer, one has to exclude the possibility of extension of the observable on the basis of the acceptance of proper theories. In other words, the transformation process of proper theories into observation theories, such as the atomic theory of matter became for nuclear physics, has then to be conceived as merely a way of speaking, giving rise to other kinds of as-if-behavior. A positive answer to the present question amounts to so-called scientific realism, according to which proper theories, or at least theoretical terms, have to be taken seriously. A negative answer might be said to reflect observational realism or just empiricism.
As a matter of fact, there are two well-known types of the negative answer to Q3. According to the first type, usually called instrumentalism, talking about reference of theoretical terms does not make sense, let alone talking about true or false (proper) theories. This way of talking reflects according to the instrumentalist a kind of category mistake by mistakenly extrapolating meaningful terminology for the observational level to the theoretical level. The only function of proper theories is to provide good derivation instruments, that is, they need to enable the derivation of as many true observational consequences as possible and as few false observational consequences as possible. Well-known representatives of the instrumentalist position among philosophers are Schlick, Toulmin (1953) and Laudan (1977). Moreover, although debatable, the physicist Bohr is a reputed instrumentalist, at least as far as quantum mechanics is concerned. Notice that it is plausible to make the distinction between an instantial and a modal version of instrumentalism depending on whether the relevant true and false observational consequences all pertain to the actual world or at least some to the real world.
According to the second type of negative answer to Q3, called (constructive) empiricism by its inventor and main proponent Van Fraassen (1980), there is no category mistake, that is, the point is not whether or not theoretical terms can refer and proper theories can be true or false. In fact such terms may or may not refer and such theories are true or false, but the problem is that we will never know this beyond reasonable doubt. Hence, what counts is whether such theories are observationally true or false. Again there are two versions, instantial and modal empiricism, according to whether the theories are supposed to deal all with the actual world or at least some with the real world. Although Van Fraassen is clear about his non-modal intentions, the modal analogue has some plausibility of its own. That is, it makes perfect sense to leave room for observational dispositions, without taking theoretical terms of other kinds seriously. In other words, if one conceives dispositions in general, hence including observational dispositions, as theoretical terms, one may well reserve a special status for observational dispositions. In both versions, it makes sense to talk about the observational truth in the sense of the strongest true observational hypothesis about a certain domain of the natural world within a certain vocabulary. Assuming that it is possible to make sense of the idea that (the observational theory following from) one theory is closer to the observational truth than another, even convergence to the observational truth is possible. As suggested, Van Fraassen is a strong defender of instantial empiricism, where it should be remarked that his attitude is strongly influenced by his interest in quantum mechanics. Although Van Fraassen extrapolates this attitude to other proper theories, there are also scientists, in fact there are many, who take advantage of the fact that there may be examples of proper theories towards which an empiricist attitude is the best defensible one, whereas there are other examples towards which a realist attitude is the best defensible one. This gives rise to what Dorling (1992) has aptly called local positivist versus realist disputes, as opposed to the global dispute about whether it is a matter of yes or no for all proper theories at the same time. In this respect the empiricist attitude is usually identified with a position in the global dispute, the realist positions that follow usually leave room for local empiricist deviations from the globally realist attitude, as a kind of default heuristic rule.
As remarked already, for both types of empiricists, the long-term dynamics in science, according to which proper theories transform into observation theories, has to be seen as an as-if way of speaking. The question even arises whether this is really a coherent way of deviating from scientific practice where it seems totally accepted that the concept of observation is stretched to the suggested theory-laden interpretation.
Hence, it is time to turn to the positive answer to Q3, that is, to the position called scientific realism. Since the books by Hacking (1983) and Cartwright (1983) there is a weaker version of realism than the traditional one, which is suggested by the next question.
Question 4: Can we claim to possess true claims to knowledge about the natural world beyond (what is observable and) reference claims concerning theoretical terms?
Whereas Hacking and Cartwright, when answering this question in the negative sense, primarily think of reference of entity terms, and call their position entity realism, it is highly plausible to extrapolate that position to attribute terms, in some plausible sense of reference, and speak of referential realism. (2) According to referential realism, entity and attribute terms are intended to refer, and frequently we have good reasons to assume that they do or do not refer. Again it is possible to distinguish an instantial and a modal version, not only with respect to observational consequences, but also with respect to theoretical terms. For instance, when one takes the existence of atoms in the actual world seriously, which goes beyond empiricism, it is also defensible to take the existence of physically possible atoms seriously, even if they do not (yet) exist in the actual world. In a sense this is just a definition of (existence in) the real world, as encompassing the actual world. Moreover, in both versions it is possible that one theory is observationally and referentially closer to the truth than another, as soon as we assume, in addition to the previous assumptions for observational truth approximation, that it is possible to define the idea that (the total referential claim of) one theory can be closer to the referential truth than another. Here, the referential truth is of course the strongest true referential claim which can be made by a certain vocabulary about a certain domain. However, since referentialists do not want to take theoretical induction seriously, that is, deciding to further assume that a certain proper theory is true (see further below), the transformation of proper theories into observation theories is for them no more open than for empiricists, i.e., it is open only in some as-if-reading. Referential realism seems, however, more difficult to defend than constructive empiricism, in particular when one takes the possibility of truth approximation into account. That is, as long as one is only willing to think in terms of true and false claims about theoretical terms when they are supposed to refer, one may be inclined to hold that most of these claims, past and future ones, are false. However, as soon as one conceives of sequences of such claims that may approach the truth, it is hardly understandable that the truth would not be a worthwhile target, at least in principle. Hence, let us turn to the suggested stronger position.
The positive answer to Q4 brings us to so-called theoretical or theory realism, in some version or another advocated by, for instance, Peirce, Popper (1963), and Niiniluoto (1987). (3) Theory realism shares with referential realism the claim that theoretical terms are supposed to refer, and that, from time to time, we have good reasons to assume that they refer, including the corresponding truth approximation claims. It adds to this the claim that theories are claimed to be true, and that we have from time to time good reasons to further assume that they are true, which is called theoretical induction. Moreover, proper theories can converge to the theoretical truth, that is, the strongest true claim that can be made, in a given vocabulary, about a specific domain, again leaving room for an instantial and a modal version. Although the truth to be approached is again domain-and-vocabulary relative, this does not exclude, of course, the possibility of comparison and translation of theories. Moreover, theoretical induction is always a matter for the time being, a kind of temporal default rule: as long as there is no counter-evidence, it is assumed to be true. This default-assumption not only implies that the theoretical terms of the theory then are assumed to refer, but also that the proper theory can from then on be used as an observation theory. Hence, the transformation process and the corresponding long-term dynamics are possible.
The last question to be considered is the following:
Question 5: Does there exist a correct or ideal conceptualization of the natural world?
In contrast to the positive answers on the questions Q2 to Q4, a positive answer to the fifth question brings us to a position that is not purely epistemologically built on the positive answer to Q1 (i.e., ontological realism), viz., it amounts to an extreme kind of metaphysical realism which we like to call essentialistic realism. The reason to call it this is, of course, that if there is an ideal conceptualization then the natural world must have essences of a kind. For instance, there must be natural kinds, not only in some pragmatic sense, but in the sense of categories in which entities in the actual or the real world perfectly fit. Philosophers of science like Boyd (1984) and Harré (1986) seem to come close to this point of view. According to this extreme form of realism, the challenge of science is to uncover the ideal conceptualization, that is, to discover and extend the ideal vocabulary, on the basis of which perfect observational, referential and theoretical truths can be formulated. Refinement of this vocabulary is not so much directed at more precise and deeper truths, but at additional truths. Of course, it is possible to restrict the idea of an ideal vocabulary to an observational vocabulary, but there do not seem to be representatives of this kind of essentialistic empiricism. It will also be clear that there is again an instantial and a modal version, but if one is an essentialist, the modal version seems to be the most plausible one.
The negative answer to Q5 gives rise to what we call constructive realism. (4) The term was already used by Giere (1985) in more or less the same way. The difference is that Giere does not take truth approximation into account. Peirce, Popper and Niiniluoto, however, do take truth approximation into account. Moreover, whereas Peirce and Niiniluoto focus on the instantial version, Popper and Giere seem to have primarily the modal version in mind, without excluding the instantial version. In our view, the modal version of constructive realism is the best fit to scientific practice. The adjective 'constructive' is used for more or less the same reason as it is used by Van Fraassen, in his case restricted to the observational level. Vocabularies are constructed by the human mind, guided by previous results. Of course, one set of terms may fit better than another, in the sense that it produces, perhaps in cooperation with other related vocabularies, more and/or more interesting truths about the domain than another. The fruitfulness of alternative possibilities will usually be comparable, at least in a practical sense, despite the possibility of fundamental incommensurability. There is however no reason to assume that there comes an end to the improvement of vocabularies.
We summarize the preceding survey in the figure below.
The main epistemological positions
We consider the positions of instrumentalism, constructive empiricism, referential realism, and theory realism to be the main epistemological positions. Restricting the attention to their modal interpretation, they have been further characterized and compared in the light of the results of the analysis of empirical progress and truth approximation in Structures in Science (manuscript). Lack of space forces us to a brief indication here, to be elaborated in the presentation.
There are good reasons for the instrumentalist to become constructive empiricist; in his turn, in order to give deeper explanations of success differences, the constructive empiricist is forced to become referential realist; in his turn, there are good reasons for the referential realist to become a theory realist. The theory realist has good reasons to choose for constructive realism, since there is no reason to assume that there are essences in the world. Notice that the road to constructive realism amounts to a pragmatic argumentation for this position.
Besides these successive steps, there appear to be good reasons for all positions not to use the falsificationist but the 'evaluationist' methodology. That is, the selection of theories should exclusively be guided by more empirical success, even if the better theory has already been falsified. Hence, the methodological role of falsifications has to be strongly relativized. This does not at all imply that we dispute Popper's claim that aiming at falsifiable theories is characteristic for empirical science, on the contrary, only falsifiable theories can obtain empirical success.
The suggested hierarchy of the heuristics corresponding to the positions is, of course, not to be taken in a dogmatic sense, that is, when one is unable to successfully use the theory realist heuristic, one should not stick to it, but try weaker heuristics, hence first the referential realist, then the empiricist, and finally the instrumentalist heuristic. For, as with other kinds of heuristics, although not everything goes always, pace (the suggestion of) Feyerabend, everything goes sometimes. Moreover, after using a weaker heuristic, a stronger heuristic may become applicable at a later stage: "reculer pour mieux sauter." Notes
(1) I would like to thank the Netherlands Institute for Advanced Study (NIAS, Wassenaar) for the ideal circumstances to write this paper, Anne Simpson for editing the English, and the members of the Promotion Club Cognitive Patterns (PCCP) in Groningen, in particular, Michel ter Hark, Erik Krabbe, Jasper Oosten and Esther Stiekema, for their useful comments.
(2) This term is used by Radder (1988), however, in a much stronger sense, viz., a strong version of constructive realism (below).
(3) See Niiniluoto (1984) for a lucid account of the relation between Popper, Peirce, and Whewell.
(4) The phrase 'nominalistic realism' would also be adequate if that were not generally conceived as a contradictio in terminis.
Boyd, R.N., (1984), "The current status of scientific realism," in: Scientific realism, ed. J. Leplin, University of California Press, Berkeley, pp. 41-82.
Cartwright, N., (1983), How the laws of physics lie, Clarendon Press, Oxford.
Dorling, J., (1992), "Bayesian conditionalization resolves positivist/realist disputes," The Journal of Philosophy, 362-382.
Giere, R., (1985), "Constructive realism," in: Images of science, eds. P. Churchland and C. Clifford, The University of Chicago Press, Chicago, 75-98.
Hacking, I., (1983), Representing and intervening, Cambridge UP, Cambridge.
Harré, R., (1986), Varieties of realism, Blackwell, Oxford.
Kuipers, T., (manuscript), Structures in Science
Laudan, L., (1977), Progress and its problems, University of California Press, Berkeley.
Niiniluoto, I., (1984), "Notes on Popper as follower of Whewell and Peirce," Is science progressive? Reidel, Dordrecht, 1984, pp. 18-60.
Thoughts on a Possible Rational Reconstruction of the Method of "Rational Reconstruction"
Gregg Alan Davia University of Stuttgar and University of Mainz, Germany
ABSTRACT: Rational reconstructions standardly operate so as to transform a given problematic philosophical scientific account-particularly of a terminological, methodological or theoretical entity-into a similar, but more precise, consistent interpretation. This method occupies a central position in the practice of analytic philosophy. Nevertheless, we encounter-even if only in a very few specific publications-a vague image of it. This is due on the one hand to the problem of the intentions of application, i.e., of the normativity of rational reconstruction (descriptive/prescriptive-ambivalence). It is also due on the other hand to the problem of the significance of the method in the field of history of philosophy (systematic/historical-dichotomy). The varied usage within analytic philosophy, as well as the increasingly inflationary and interfering usage outside, contribute to make rational reconstruction somehow appear a Proteus in contemporary philosophical methodology. This paper attempts to administer first aid and to close a bit of the theoretical gap and thus to reach a more exact image for the interests of analytic philosophy. Self-application of the method appears to be the right remedy. A graduating rational reconstruction of a standard concept of rational reconstruction will be suggested, differentiating the concept of rational reconstruction according to normativity, and explicating the method of rational reconstruction into two such variants.
The method of rational reconstruction occupies a central position in the practice of Analytical Philosophy. Andreas Kamlah once has dealt with it in an article under the indicative title "Wie arbeitet die analytische Wissenschaftstheorie?" or, in English, "How does Analytical Philosophy of Sciene operate?" (see Kamlah ). Nevertheless, we encounter-even in the specific publications-only a vague image of it. Surprisingly, there are comparatively few specific publications. Historically they concentrate in the phase of Logical Empiricism. On the other hand we record a quite extensive literature on the latest variant of rational reconstruction, the "structuralist reconstruction." Besides Kamlah's article, Poser  is to be mentioned. Further, for Analytical Philosophy directly relevant material includes mainly brief remarks in preliminaries and digressions, particularly in works of Wolfgang Stegmüller, who established the method in German postwar philosophy. I want to point out his well-known article on Kant (Stegmller ), which I followed when choosing a title for this paper, as well as his introduction to the fourth volume of his great series on philosophy of science and Analytical Philosophy with its section "Neue Betrachtungen ber die Ziele und Aufgaben der Wissenschaftstheorie" (Stegmller , pp. 1-64). Jrgen Mittelstra has commented for German Constructivism in some other articles (Mittelstra [1985a], Mittelstra [1985b]). Consequently, a general, problemizing and coherent "Theory of Rational Reconstruction" that really would deserve the name (as well as by the way any kind of "Textbook of Rational Reconstruction") has, as it seems, remained a desideratum. The varied usage within Analytical Philosophy as well as the increasingly inflationary and interfering usage outside contribute in addition, to make rational reconstruction appear a Proteus or a black box in philosophical methodology.
This paper tries-besides creating some appreciation of the difficulties-to administer first aid and-by analysis of one of the two main problems of the method-to close a little bit of the theoretical deficit gap and thus to reach a more exact image for the interests of Analytical Philosophy. As main problems (1) the issue of the intentions of application, i.e., of the normativeness of rational reconstructions (the descriptive/prescriptive-ambivalence, especially in Stegmller  and Kamlah ), and (2) the issue of the areas of application, i.e., of the significance of the method in the field of history of philosophy (the systematic/historical-dichotomy, especially in Poser ), have come under discussion. In a broader sense, the second issue also includes the reconstructive discussions within history of science and the discussions about the reconstruction of non-apophantic entities; it then perhaps could be called the "systematic/ hermeneutic-controversy." According to its title this outline is to be understood as a self-application of the method at issue; therefore we will proceed in the following manner: First of all, a semantic preconception of the method of rational reconstruction has to be produced. We shall recur to a standard concept. On this basis then, the problem of normativeness of rational reconstructions will be taken up again and treated. A graduating rational reconstruction of the standard concept will be suggested. Finally, some residual and succeeding problems are to be pointed out.
Semantic Preliminaries, Or: A Standard Concept Of "Rational Reconstruction"
A rational reconstruction presupposes-this can already be said by intuition-acquaintance with a preceding object. Analogously, a rational reconstruction of rational reconstruction will presuppose a preceding concept of rational reconstruction itself. Such a semantic preconception can be produced in three manners:
First, a historical stocktaking of usage can be carried out. One then achieves a history of the reconstructive concepts. They have by no means been used with clear distinction and therefore will require a systematic analysis and coordination as a concept family. This is hardly to be managed adequately within this paper; we will have to content ourselves with the mere enumeration of the most important elements.
The starting point of the concept history regarding Analytical Philosophy is constituted by Rudolf Carnap's "rationale Nachkonstruktionen" within Logical Empiricism. According to Carnap "rationale Nachkonstruktionen" show knowledge, which he considers to be even in science mostly of intuitive nature, in its "formal structure" and thus transform it into the "rational form of logical inferences." With the thereby realized "separation between the pure given and the intellectual processing" intuition is given a rational justification. (Cf. Carnap , pp. 138 f.-Translations by myself.) A subclass of this is "explication" as rational reconstruction of concepts, for which Carnap gives similarity, exactness, fruitfulness and simplicity as criteria of adequacy. (Cf. Carnap , pp. 1 ff.) As described by Kamlah, Hans Reichenbach contrasts a "rationale Rekonstruktion," with a "logische Analyse." According to Reichenbach, the first is exclusively orientated towards someone else's scientific thoughts, whereas the latter is explicitly based on one's own judgement. (Cf. Kamlah , pp. 26 ff.) In the more recent philosophy of science the concepts of "logical reconstruction" (with the main emphasis on using formal logic) and "structuralist reconstruction" (as rational reconstruction based on the structuralist conception of theories by Sneed and Stegmller (see e.g., Diederich )) have dominated the scene. Particularly, the method has played an extremely important part in the discussion of Thomas S. Kuhn's history of science, actually within Imre Lakatos' alternative conception of "scientific research programmes" on the one hand, in Stegmüller's structuralist reconstruction of Kuhn's theory on the other hand. (See e.g., Lakatos  and Stegmller  respectively.) A part of this terminology is also used outside, within other philosophical schools. Particularly, Constructivism understands by "rational reconstruction" the confirming realization of action, speech and science as something people have in common. Such rational reconstructions are based on elementary experiences of human life and carried out in logical steps within a constructive "Orthosprache," which ultimately recurs to common action. (Cf. Lorenzen/Schwemmer , pp. 9 ff.) Furthermore, so-called "Critical Theory" ("Frankfurt School") has tried to seize hold of the concept of reconstruction, but obviously without connecting a discernible comprehensive conception to it. (Cf. e.g., Habermas , pp. 363-370 ("Bemerkungen zum Verfahren rationaler Nachkonstruktion") and pp. 371-385 passim ("Rekonstruktive vs. empiristische Sprachwissenschaft").) This is the transition to a so to speak "modish" usage. "Reconstructions" can nowadays be found in nearly every philosophical work, frequently with some changing attributes, but hardly ever with a sufficient explanation of what really happens. We are confronted with creations like "historical reconstruction," "critical reconstruction" or "social construction by reconstruction." Second, a pragmatically orientated analysis can take place, i.e., an enquiry into the practice of alleged applications. Besides the obvious philosophical examples we have applications in various other disciplines, e.g., in literary studies or in economic theory. However, this way can't be taken within this paper either.
What remains, is, third, the recourse to a standard concept of rational reconstruction, i.e., to a concept that has repeatedly played an important part in the discussions. Such a standard concept can be obtained from Stegmller's article on Kant (cf. Stegmller , pp. 1 ff.) and also from Poser's short entry in Speck's encyclopaedia of philosophy of science (cf. Poser ). According to this, a rational reconstruction presents a given problematic complex (the object of reconstruction-with special regard to the area of philosophy of science one may think, like Kamlah, of terminological, methodological or theoretical entities) in a similar, but more precise and more consistent formulation (the product of reconstruction).
This standard concept, as the semantic premise of reconstruction, constitutes the basis of the following reflections. But it should have become clear, that some other possible semantic premises and-if only because of that-possible rational reconstructions of the method of rational reconstruction remain conceivable.
On The Problem of Normativeness, Or: A Graduating Rational Reconstruction of the Standard Concept of Rational Reconstruction
For a long time there has been a quarrel within Analytical philosophy of science as well as e.g., between it and Constructivism, whether or to what extent philosophy of science is a prescriptive activity. Naturally, this quarrel has mainly taken the course of a methodological controversy.
An in a number of places quite surprising historical analysis referring to the familiy of reconstructive concepts has been presented by Kamlah with regard to the early Carnap and to Reichenbach. According to Kamlah the equation "analytic = descriptive" proves absurd in the light of history, as Carnap's early "rationale Nachkonstruktion" as well as Reichenbach's "logische Analyse" served the examination or justification of scientific operations. (Cf. Kamlah , p. 25 and pp. 28 ff.) Of course such a historical argumentation cannot imply any commitment at all, since it forms a clear case of genetic fallacy, for which by the way Reichenbach himself (with his distinction between "context of discovery" and "context of justification") could be consulted as a main authority. Some systematic statements in Stegmller and in Poser regarding the method of rational reconstruction turn out ambivalent. According to Stegmller and Poser rational reconstructions are neither purely descriptive nor purely prescriptive. (Cf. Stegmller , p. 8, resp. Poser , p. 555.) Stegmller provides an itemization of types of strongly prescriptive operations, e.g., the demonstration of circular definitions (cf. Stegmller , pp. 11 ff.), and Poser points out some fundamental prescriptive implications of rational reconstructions, like the evaluation of terminology or the choice of logic (cf. Poser , p. 556). But regrettably, both authors fail to give a really satisfying explication and explanation of the actual ambivalence.
A solution to this problem by relating it to the objects of reconstruction has been submitted by Kamlah. According to this a "logical reconstruction"-Kamlah obviously uses this concept in his abstract as a synonym for Reichenbach's concepts of "rationale Rekonstruktion" and of "logische Analyse" (cf. Kamlah , p. 1 and p. 32).
(1) of concepts is mainly descriptive (since concepts, as e.g., "light" or "sound," can't be true or false, an explicans for such an intuitively given concept requires an empirical survey of usage (cf. Kamlah , pp. 32 ff.));
(2) of methods is mainly prescriptive (one has to ascertain the usage of a method, as e.g., the "argument by analogy," too, but then one has to estimate its suitability, which creates a prescriptive component that is not included in the reconstruction of concepts (cf. Kamlah , pp. 32 ff.));
(3) of theories is-depending on intention-descriptive or prescriptive (the assumption of truth resp. reliability is the prerequisite of a purely descriptive reconstruction, in any other case the intention of the observer will make the reconstruction of a theory turn out prescriptive (cf. Kamlah , pp. 36 ff.)).
For reasons of space I have to dispense with putting forward my special objections against Kamlah's argumentation, and confine myself to my general doubts about its adequacy. Kamlah's solution, I fear, is oversimplified, since it disregards the fundamental operativeness of the criteria of adequacy-as included in the here presupposed standard concept. Kamlah himself doesn't base his solution on an explicit semantic preconception, as the semantic function of his historical digression remains unclear. Stegmller  and Poser  by the way also lack an operational-criteriological analysis of this complex. Thus Kamlah comes to treat descriptivity and prescriptivity somehow as if they formed an inclusive disjunction, which rather represents an escamotage than an explication of the ambivalence of the concept of rational reconstruction. A clarification within a preceeding concept of reconstruction with its operative options is indispensable, for otherwise any talking about a uniform method, i.e., one that doesn't depend on the special applications, would seem unreasonable. A qualification with respect to the objects may be a depending second step.
Regarding the standard concept, the descriptive/prescriptive-ambivalence occurs as polarity or inconsistency between the criteria of adequacy, i.e., between the descriptive requirement of similarity on the one hand and the prescriptive elements of precision and consistency on the other hand. In order to clarify this polarity I would like to suggest a graduating rational reconstruction of rational reconstruction that elementarily unfolds the concept and method of rational reconstruction with two with regard to their normativeness graduated explicantia resp. that differentiates correspondingly between two such variants of the method.
Consider the qualitatively, i.e., with reference to the supposed intention of the object of reconstruction, determined change of the informational content of the object of reconstruction to be the yardstick on normativeness. One may then distinguish basically between rational reconstructions of the first and of the second degree. A "rational reconstruction of the first degree" is dominated by the descriptive impetus, i.e., by the requirement of similarity, which here has to be strictly interpreted as a criterion of material non-creativity. Rational reconstruction as a rational "again"-construction ("re-" as "again") is interested in making an object "more equal to itself," e.g., by extracting essential elements and reformulating and restructuring them. Its task is revealing formal or representational problems and managing them by realizing immanent possibilities to improve precision and consistency of the object of reconstruction. The problem of normativeness reduces to operational problems as the above-mentioned fundamental prescriptive implications of rational reconstructions outlined by Poser. For convincing illustrations one may consult the rational reconstructions by Ulrich Druwe in the area of political philosophy (see Druwe  and ).
A "rational reconstruction of the second degree" is dominated by the prescriptive impetus, i.e., the pursuit of precision and consistency, which here have to be interpreted as even material criteria of creativity. Rational reconstruction as rational "new"-construction ("re-" as "new-") is interested in a material correction resp. improvement by external formal criteria. The descriptive component reduces in the extreme case to the mere factuality of initial material, exactly the object of reconstruction, which is subjected to the instruments of precision and consistency improvement. (The concession of such a minimum similarity certainly requires a very liberal concept of similarity.) No or a decisively diminished "feedback" (This cybernetic notion of rational reconstruction has been introduced by Stegmller (cf. e.g., Stegmller , p. 14).) between object and product of reconstruction is carried out. For an illustration one may consult Stegmller's structuralist reconstruction of Kuhn's history of science, which really contains some clear (and, in my opinion, innovative) reinterpretations of essential concepts and therefore abandons Kuhn's original intention (cf. the corresponding critique in Baumgardt-Thom , pp. 110 ff.).
A conceivable further differentiation into 2+n degrees should be orientated to the extent of (increasing) prescriptivity. It could also be complementarily developed with reference to descriptivity. But prescriptivity of course is the philosophically decisive aspect, which becomes evident if one thinks of the theoretical maximum of similarity as mere paraphrase (which certainly lies beyond the method of rational reconstruction).
Some Residual and Succeeding Problems
The graduating rational reconstruction provides, in my opinion, a similar, but more precise and more consistent version of the chosen standard concept of rational reconstruction. It is similar to the standard concept, because it is developed with reference to its criteria of adequacy. And it is more precise and more consistent than the standard concept, because it explicates its normative variability. Furthermore, it applies to all systematic objects of application and may integrate Stegmller's itemization of prescriptive operations as well as Poser's fundamental prescriptive implications. Thus it constitutes a possible rational reconstruction of the method of rational reconstruction. However, the received product of reconstruction doesn't remain unproblematic. Residual and succeeding problems occur; I would like to specify the most important:
First, the problem of normativeness can be iterated, which implies the question of self-application, i.e., of the degree of the graduating rational reconstruction of rational reconstruction.
Second, with regard to application, the problem of measurability of formal or material processing of objects of reconstruction deserves consideration. The concepts of "intention" and of "informational content" imply known as well as new vagueness. An exactly differentiated graduation will require similarity, precision and consistency to be describable not only as comparative, but as quantitative or even metric concepts. For an illustration of this problem one may think of the theoretical possibility of a degree of rational reconstruction that contains descriptive and prescriptive components ana partes aequales. Third, a closer enquiry into the relations between the graduating rational reconstruction of rational reconstruction and Reichenbach's distinction ("rationale Rekonstruktion" vs. "logische Analyse") seems to suggest itself.
Finally, and in connection with all the other points, a careful examination of the fruitfulness of the presented graduating rational reconstruction for operating the systematic/historical-dichotomy remains desirable.
A part of the answer to the question of the perspectives of Analytical Philosophy, is devoted to and will necessarily be constituted by methodological reflection. It is a matter not of dogmatism, but of a sound, in principle dynamic and by the way didactically communicable canon. Such a canon must distinguish itself in the best Analytical tradition by lucidity, i.e., by precision and consistency. This brief discourse has been intended to stimulate a corresponding discussion.
Baumgardt-Thom, Yvonne : Das Problem der Geisteswissenschaften in der analytischen Philosophie und Wissenschaftstheorie. Unter besonderer Bercksichtigung der Rekonstruktion der Hermeneutik, Meisenheim am Glan 1978 (Diss. Dsseldorf 1977)
Carnap, Rudolf : Der logische Aufbau der Welt, Berlin-Schlachtensee 1928
________. : Logical Foundations of Probability, 2nd ed. London 1951 Diederich, Werner : Strukturalistische Rekonstruktionen. Untersuchungen zur Bedeutung, Weiterentwicklung und interdisziplinren Anwendung des strukturalistischen Konzepts wissenschaftlicher Theorien, Braunschweig 1981
Druwe, Ulrich : Vertragstheorie als Staatslegitimation. In: Archiv fr Rechts- und Sozialphilosophie 74 (1988), pp. 394-399
________ : Politische Theorie, 2nd ed. Neuried 1995
Habermas, Jrgen : Was heit Universalpragmatik? In: Habermas, Jrgen: Vorstudien und Ergnzungen zur Theorie des kommunikativen Handelns, Frankfurt a. M. 1984, pp. 353-440 (first publ. 1976)
Kamlah, Andreas : Wie arbeitet die analytische Wissenschaftstheorie? In: Zeitschrift fr allgemeine Wissenschaftstheorie 11 (1980), pp. 23-44
Lakatos, Imre : The Methodology of Scientific Research Programmes. Philosophical Papers I. Ed. by John Worrall and Gregory Currie, Cambridge 1978 Lorenzen, Paul/ Schwemmer, Oswald : Konstruktive Logik, Ethik und Wissenschaftstheorie, Mannheim 1973
Mittelstra, Jrgen [1985a]: Scientific Rationality And Its Reconstruction. In: Nicolas Rescher (ed.): Reason and Rationality in Natural Science, Lanham 1985, pp. 83-102
________ [1985b]: ber den Begriff der Rekonstruktion. In: Ratio 27 (1985), pp.71-82
Poser, Hans : Philosophiegeschichte und rationale Rekonstruktion. Wert und Grenze einer Methode. In: Studia Leibnitiana 3 (1971), pp. 67-76
________ : "Rekonstruktion, rationale." In: Speck, Josef (ed.): Handbuch wissenschaftstheoretischer Begriffe. Band. 3, Gttingen 1980, pp. 555-556
Stegmüller, Wolfgang : Gedanken ber eine mgliche rationale Rekonstruktion von Kants Metaphysik der Erfahrung. Teil I. Kants Rtsel der Erfahrungserkenntnis. In: Ratio 9 (1967), pp. 1-30
________ : Probleme und Resultate der Wissenschaftstheorie und Analytischen Philosophie. Band IV. Personelle und Statistische Wahrscheinlichkeit. Studienausgabe Teil A, Berlin 1973
________ : Probleme und Resultate der Wissenschaftstheorie und Analytischen Philosophie. Band II. Theorie und Erfahrung. Studienausgabe Teil E, 2nd ed., Berlin 1985. Disponible en: http://www.bu.edu/wcp/Papers/Scie/ScieDavi.htm
La Complejidad: Consideraciones Epistemológicas y Filosóficas
Elba del Carmen Riera Universidad Nacional de Santiago del Estero, República Argentina
ABSTRACT: La ciencia no puede escapar al condicionamiento cultural. Desde hace unos treinta años ha surgido un interés particular por una nueva línea de investigación que privilegia un objeto de estudio interdisciplinar: los sistemas complejos. Se trata de una respuesta al cambio cultural frente a conceptos como los de desorden y caos que estaban desplazados del ámbito de la ciencia clásica, por ser considerarlos informes y vacíos de significación. Hoy hay toda una revalorización de los mismos. Los sistemas complejos se ubican entre la categoría de orden entendida como sinónimo de determinismo y previsibilidad total de la naturaleza y el caos, concebido como azar y desorden total, donde nada puede ser previsto. La complejidad, en cambio, supone irreversibilidad, temporalidad, no-linealidad, aleatoriedad, fluctuaciones, bifurcaciones, autoorganización, probabilidad y extrae de esta nueva información, una enorme riqueza de posibilidades para hacer crecer la ciencia. Intentamos resumir los caracteres fundamentales de este nuevo paradigma que, por medio de un nuevo lenguaje epistemológico postula la creación de categorías y conceptos diferentes para la ciencia actual, lo que se está traduciendo en una ampliación de la racionalidad científica, Partimos de la afirmación que sostiene que uno de los condicionamientos básicos de los modelos y teorías científicas es cultural. En el contexto actual, podemos constatar que diferentes disciplinas, lo suficientemente apartadas entre sí, como para que la influencia directa aparezca como improbable, se han dedicado a estudiar problemas similares y basan sus formulaciones en supuestos isomórficos.
Esto se genera porque las preocupaciones que las sustentan están fuertemente cargadas de significación dentro del contexto cultural imperante. Nos referimos al interés despertado en las ciencias por los sistemas no-lineales, la irreversibilidad, el desorden, lo que algunos científicos prefieren llamar: el nuevo paradigma de la complejidad.
Investigadores de diversas disciplinas, interdisciplinariamente, desde hace unos treinta años han comenzado a interesarse por explorar sus fecundas posibilidades.
Esta nueva línea de investigación parte de la convicción de que la no-linealidad está por todas partes en la naturaleza, contrariamente a lo que sostenía la ciencia clásica para quien era una excepción. Por el contrario, son los sistemas cerrados y estables, los que constituyen la excepción.
Estos problemas estuvieron largamente proscriptos de la ciencia clásica. El concepto de caos, se asociaba con lo informe, vacío y desordenado y en todo caso con la ignorancia e imprecisión humana.
Creemos que hoy están dadas las condiciones culturales para una revalorización conceptual que integre orden y desorden, reversibilidad e irreversibilidad, linealidad y no-linealidad. Se trata de quitarles una significación dialéctica opositora para alcanzar un orden más complejo, más rico y fecundo, que ostenta profundas estructuras codificadas con enormes posibilidades de información.
Nuestra intención, en este trabajo, consiste en extraer algunas consecuencias epistemológicas que posibiliten una amplitud de la racionalidad científica que dé cabida a la riqueza conceptual y metodológica que promete el paradigma de la complejidad.
Intentamos sintetizar a través de diez características los aspectos fundamentales de esta fecunda linea de investigación.
Nos guiamos especialmente por las investigaciones de la escuela de Bruselas, liderada por Ilya Prigogine y sus colaboradores, pero que ya se ha extendido a muchos otros grupos de trabajo.
I. Cuestionamiento de Algunos Presupuestos del Paradigma Clásico de la Ciencia (Baconiano-Cartesiano-Newtoniano)
La ciencia clásica privilegiaba el orden, el determinismo, la regularidad, la legalidad, la estabilidad y previsibilidad de la naturaleza. Su aspiración era descubrir lo inmutable, lo permanente, más alla de las apariencias del cambio. Las leyes universales de la dinámica clásica fueron conservadoras, reversibles y deterministas. La definición de un estado del sistema y el conocimiento de la ley que rige la evolución, permitían deducir, con la certeza y la precisión de un razonamiento lógico, la totalidad tanto de su pasado como de su futuro. El ideal de la ciencia clásica se encarnó en las trayectorias y en el diablillo de Laplace que las contempla durante un instante y las calcula para la eternidad. Sin embargo, hoy se sabe que las trayectorias que parecen tan reales son idealizaciones: el mundo reversible es sólo un caso particular de la realidad.
II. Incorporación de la Irreversibilidad y la No-linealidad como Constituyentes Intrínsecos de la Realidad
El nuevo paradigma representa un reto a la reversibilidad. En un mundo determinista, la irreversibilidad no tendría sentido, ya que el mundo de mañana estaría ya contenido en el mundo de hoy. Con la Termodinámica, surge el desafío a la física clásica; la segunda ley hace la clara diferencia entre procesos reversibles e irreversibles, que denotan la existencia de la flecha temporal. Al definir la entropía se dá un paso importante para comprender la irreversibilidad. Se hace posible la introducción del tiempo y la historia en un universo que la física clásica había descripto como eterno. Durante bastante tiempo, muchos científicos pensaron que las leyes fundamentales de la física sólo permitían deducir que los sistemas deben llegar al equilibrio termodinámico, y que el proceso de evolución biológica era una rara excepción. Hoy, en cambio, se sabe que los sistemas abiertos, es decir, los que intercambian materia y energía con el mundo exterior, son los más numerosos."En este fin de siglo, somos cada vez más los que estimamos que las leyes fundamentales son irreversibles y aleatorias, mientras que las leyes determinísticas y reversibles, de las que no discutimos su existencia, no se aplican más que a situaciones límite: procesos "ejemplares" en el sentido en el que lo son los cuentos simplificados que les presentamos a los niños antes de confrontarlos con problemas reales." (1)
En esta cosmovisión, la aleatoriedad, tiene un papel que desempeñar, porque las fluctuaciones que se producen cerca de un punto de bifurcación pueden hacer que un sistema tome un rumbo diferente al que habría tomado de no mediar esas fluctuaciones. Esta característica es intrínseca a la realidad, por lo tanto la comprensión que la física clásica hace del universo es incompleta y el precio que se pagó por ella fue idear un reino intemporal, divorciado de la experiencia humana.
III. El Caracter Evolutivo y Creativo de la Realidad
La noción de ley de la naturaleza, en la física clásica, se refiere a un universo fundamentalmente reversible, en el que no hay diferencia entre pasado y futuro. En esta perspectiva, una ley de la naturaleza se asocia a una descripción determinista y reversible en el tiempo. En su formulación tradicional, las leyes de la física describen un mundo idealizado, un mundo estable, y no el mundo inestable, evolutivo, en el que vivimos. Este punto de vista nos obliga a reconsiderar la validez de las leyes fundamentales. Hoy se debe incorporar en nuestras leyes físicas, la dimensión evolutiva, asociada con la entropía. La entropía es el elemento esencial que aporta la termodinámica, ciencia de los procesos irreversibles, es decir orientados en el tiempo. Estos procesos poseen una dirección privilegiada en el tiempo, en contraste con los procesos reversibles. La naturaleza nos presenta procesos irreversibles y reversibles, pero los primeros son la regla y los segundos la excepción. Durante las últimas décadas se ha abierto un concepto nuevo: la noción de inestabilidad asociada a la de "caos." La palabra caos está muy cargada de un significado negativo; hace pensar en desorden incompatible con la previsión, pero no es así. Al contrario, se puede incluir el "caos" en las leyes de la naturaleza, pero siempre y cuando se generalice esta noción incorporándole las de probabilidad e irreversibilidad. El caos siempre es consecuencia de inestabilidades que introducen aspectos nuevos esenciales. Los desarrollos recientes de la física y de la química de no-equilibrio muestran que la flecha del tiempo puede ser fuente de orden. "La vida sólo es posible en un universo alejado del equilibrio." (2)
Hoy la ciencia busca en los procesos irreversibles otra clave distinta para comprender a la naturaleza, y entiende al mundo como poblado por seres capaces de evolucionar e innovar, por seres cuyo comportamiento no puede considerarse absolutamente previsible y controlable. Prigogine sostiene que las leyes de la naturaleza, no están todas "dadas" desde el pincipio, sino que evolucionan como lo hacen las especies. A medida que las cosas se complican, aparecen bifurcaciones, amplificaciones, fluctuaciones y emergen nuevas leyes. "Las raíces de lo biológico se hunden en la materia mucho antes de lo que hubiera podido imaginarse" (3) El papel activo de la irreversibilidad, la creación de un orden por fluctuaciones, el carácter aleatorio de éstas, la historicidad - es decir el papel del pasado- introducido por el orden de sucesión de las bifurcaciones que conducen a una estructura, constituyen un conjunto de notables propiedades de la evolución, características de los sistemas alejados del equilibrio.
IV. El Caracter Constructivo y de la Riqueza Informativa de los Sistemas Complejos
Estos fenómenos, por el contrario, tienen un papel constructivo muy importante. Ilya Prigogine ha recibido el Premio Nobel 1977 gracias al descubrimiento de las "estructuras disipativas" que constituyen fenómenos de comportamiento espontáneo coherente. Descubrió que en los sistemas alejados del equilibrio emergen órdenes nuevos, con lo que nos enfrentamos a un fenómeno de estructuración correspondiente a un alto nivel de cooperatividad desde el punto de vista molecular. Hoy se sabe que este fenómeno de organización está muy difundido en la naturaleza. Se trata de fenómenos sumamente ricos que presentan comportamientos periódicos en el tiempo, rupturas espontáneas de homogeneidad espacial o fenómenos aún más complejos. La materia en equilibrio es ciega, mientras que muy alejada del equilibrio, detecta las minúsculas diferencias, que son esenciales para la construcción de sistemas altamente coherentes y complejos. Se les reconoce una cierta autonomía, que permite hablar de fenómenos de "autoorganización."
Al enfatizar el papel del azar y el caos en la creación de las estructuras, Prigogine hace referencia a un universo donde los objetos están menos definidos que en la física clásica. Con ello, en lugar de evitar la no-linealidad y la complejidad, se dispone de sistemas más flexibles, rápidos y ricos, pues prometen comportamientos inesperados que presentan una amplia gama de posibilidades
V. Necesidad de un Nuevo Bagaje Conceptual Teórico y Metodológico
Es necesario construir un lenguaje nuevo, para poder interpretar esta nueva cosmovisión. Nociones como las de inestabilidad, sensibilidad a las condiciones iniciales, bifurcaciones, fluctuaciones, turbulencias, sistemas alejados del equilibrio, auto-organización, "estructuras disipativas," entre otros, tienen importancia decisiva en esta nueva línea de investigación y nos obligan a precisar sus alcances e interpretaciones.
La nueva teoría necesita cambiar la descripción de situaciones individuales (trayectorias, funciones de onda) por descripciones estadísticas y exige formulaciones matemáticas originales. Durante siglos, las trayectorias fueron consideradas los objetos fundamentales de la física clásica: ahora aparecen detentando una validez limitada. La nueva formulación de la mecánica clásica requiere de una extensión de su marco matemático, hoy en pleno auge.
VI. Interdisciplinariedad del Nuevo Objeto Epistemológico
Es en las intersecciones entre disciplinas, y a propósito de la convergencia entre vías separadas, donde han resurgido problemas renovados de antiguas preguntas, anteriores al enclaustramiento disciplinario. Prigogine aboga para que la fecundidad de las comunicaciones entre interrogaciones filosóficas y científicas deje de verse frustrada por separaciones o destruida por enfrentamientos. Ningún límite definitivamente fijado detiene de manera estable la diferenciación entre interrogaciones científicas y filosóficas, aunque no por ello se trata de identificarlas o destruir su diferenciación. La interrogación científica está sometida al diálogo experimental que limita la libertad del científico, quien no hace lo que quiere, ya que la naturaleza se encarga de desmentir las más seductoras hipótesis. Para la filosofía, por su parte, se trata igualmente de una diligencia experimental, pero no de una experimentación sobre la naturaleza sino sobre los conceptos y sus articulaciones, sobre el planteamiento de los problemas y sus consecuencias, con el mayor rigor posible.
La nueva temática, salva las fronteras entre las disciplinas científicas, ya que por ser una ciencia de la naturaleza global de los sistemas, ha reunido a pensadores de campos muy separados y ha detenido la superespecialización que parecía inminente en la ciencia.
VII. Tematización del Tiempo como Categoría Fundamental de todos los Niveles de la Realidad
El desarrollo espectacular de la física de no-equilibrio, de los sistemas dinámicos inestables, asociados a la idea de caos, nos obligan a revisar la noción de tiempo que se formuló desde Galileo. Después de tres siglos, la física ha vuelto a encontrar el tema de la multiplicidad de los tiempos. La física de hoy no niega el tiempo; es más, reconoce el tiempo irreversible de las evoluciones hacia el equilibrio, el tiempo bifurcante de las evoluciones por inestabilidad y hasta el tiempo microscópico que manifiesta la indeterminación de las evoluciones físicas y microscópicas.
VIII. Universo Participativo: Sujeto como Espectador y Actor
Para la física clásica el observador se situaba en una posición desencarnada y el objeto descrito, desde una posición de sobrevuelo. En la objetividad científica tradicional estaba implícita una voluntad de dominio para la cual el mundo estaba separado de nosotros. Hoy, las demostraciones de imposibilidad, en teoría de la relatividad, en mecánica cuántica o en dinámica, nos han enseñado que no se puede describir la naturaleza "desde el exterior," como meros espectadores. La descripción es una comunicación y está sometida a ligaduras muy generales que la física puede aprender a reconocer porque nos identifican como seres situados en el mundo físico.
Cuando se trata de descripciones de sistemas complejos, vivos y sociales, una descripción "desde lo alto," está totalmente excluida. Prigogine nos habla del "reencantamiento de la naturaleza": sostiene que siendo seres temporales y espontáneamente creados, formamos parte integral del movimiento temporal y espontáneamente organizado de la naturaleza, en vez de ser un accidente poco probable.
IX. Fin de las Certidumbres de la Ciencia Clásica
La física clásica vinculaba el conocimiento científico a la certidumbre, ya que en ciertas condiciones iniciales apropiadas se garantizaba la previsibilidad del futuro y la posibilidad de retrodecir el pasado. Con ello se alcanzaba la certidumbre. La novedad, la elección, la actividad espontánea eran sólo apariencias relativas al punto de vista humano. Sin embargo, hoy se sabe que no se pueden prever con certeza los caminos de la naturaleza: la parte accidental es irreducible. Pequeñas diferencias, fluctuaciones insignificantes pueden invadir todo el sistema y engendrar un nuevo régimen de funcionamiento. En los sistemas inestables las leyes de la naturaleza se tornan fundamentalmente probabilistas. Expresan lo que es posible, y no lo que es "cierto." La predicción que podemos hacer del futuro es una mezcla de determinismo y probabilidades." El futuro es incierto, más incierto aún de lo que hacía presagiar la mecánica cuántica tradicional con la relaciones de incertidumbre de Heisenberg." (4) En la cosmovisión de Prigogine, el futuro no puede estar determinado porque está sometido al azar, a las fluctuaciones, a las bifurcaciones y amplificaciones. Prigogine sostiene que se trata de un nuevo "principio de incertidumbre," que sostiene que más allá de cierto umbral de complejidad, los sistemas siguen rumbos imprevisibles, pierden sus condiciones iniciales y no se pueden invertir ni recobrar. Este modo de mirar a la naturaleza es un verdadero reconocimiento de sus posibilidades creativas.
El sentido de nuestro saber ha cambiado, cuando se incorpora la inestabilidad, la significación de las leyes de la naturaleza cobra un nuevo sentido. En adelante expresan posibilidades, no certidumbres. Prigogine recuerda al héroe de "El nombre de la rosa," Guillermo de Baskerville, para quien descifrar el mundo tiene algo de historia policíaca, ya que se trata de un juego intelectual en el que sólo tenemos indicios pero nunca la totalidad de los elementos. Es nuestra acción la que construye el futuro y tenemos una responsbilidad a asumir. Vivimos en un mundo peligroso e incierto que no inspira confianza ciega, pero que agudiza las oportunidades de ejercitar nuestra acción responsable y valiosa.
X. Ciencia Abierta, Que Posibilite la Ampliación de la Racionalidad Científica
La ciencia es un diálogo con la naturaleza. Pero el conocimiento no sólo presupone un vínculo entre el que conoce y lo conocido, sino que haya una diferencia entre pasado y futuro. La realidad del devenir es la condición de nuestro diálogo con la naturaleza. Hoy sabemos que la entropía y el no-equilibrio nos enseñan algo fundamental sobre la estructura del universo: que la irreversibilidad pasa a ser un elemento fundamental. "Si la descripción fundamental se hiciese en términos de leyes dinámicas estables, no tendríamos entropía, pero tampoco coherencia debida al no equilibrio, ni posibilidad de hablar de estructuras biológicas, y por lo tanto tendríamos un universo del que estaría excluido el hombre." (5)
Las ciencias se han liberado de una racionalidad cerrada. Estan ahora abiertas a lo imprevisto, al diálogo con una naturaleza que no puede ser dominada con una mirada teórica, sino solamente explorada; con un mundo abierto al cual pertenecemos y en la construcción del cual participamos. "La actividad humana, creativa e innovadora, no es ajena a la naturaleza. Se la puede considerar una ampliación e intensificación de rasgos ya presentes en el mundo físico, que el descubrimiento de los procesos alejados del equilibrio nos ha enseñado a descifrar." (6) Hoy la ciencia se afirma como ciencia humana, ciencia hecha por los hombres para hombres. En "Las leyes del caos" sostiene: "El mensaje de esta obra es optimista. La ciencia empieza a ser capaz de describir la creatividad de la naturaleza, y hoy el tiempo ya no habla de soledad, sino de alianza entre el hombre y la naturaleza descrita por él." (7)
Prigogine propone construir" una vía estrecha entre dos concepciones que conducen a la alienación, la de un mundo regido por leyes que no otorgan lugar alguno a la novedad, y la de un mundo absurdo, acausal, donde nada puede ser previsto ni descrito en términos generales." (8) Se trata de hacer emerger una descripción intermedia situada entre dos extremos: un mundo determinista por un lado, y un mundo arbitrario sometido únicamente al azar, por el otro. Las leyes físicas corresponden a una nueva forma de inteligibilidad, expresada en las representaciones probabilísticas. Se asocian con la inestabilidad y describen los acontecimientos en cuanto posibles, sin reducirlos a consecuencias deducibles y previsibles de leyes deterministas. "Discernimos nuevos horizontes, nuevas preguntas, nuevos riesgos. Vivimos un momento privilegiado de la historia de la ciencia." (9) Notes
(1) Prigogine,Ilya: El tiempo y el devenir, Gedisa, 1996, pag. 171
(2) Prigogine,Ilya: El fin de las certidumbres, Andrés Bello Santiago de Chile, 1996. pag. 30.
(3) Prigogine, Ilya: El tiempo y el devenir, pag. 174.
(4) Prigogine, op. cit. pag. 95.
(5) Prigogine, op.cit. pag. 108.
(6) Prigogine: El fin de las certidumbres, pag. 78.
(7) Prigogine: Las leyes del caos, pag. 113.
(8) Prigogine, Ilya: Elfin de las certidumbres, pag. 209
(9) Prigogine: op. cit. pag. 211.
Prigogine, Ilya: Non-equilibrium Statistical Mechanics, John Wiley, New York,1962.
Nicolis y Prigogine: Self-Organization in Nonequilibrium Systems, John Wiley, New York,1977.
Prigogine,Ilya: From Being to becoming, Freeman and company, San Francisco, 1980.
Prigogine y Stengers: La nueva alianza, Alianza, Madrid, 1983
Prigogine y Stengers: Tan sólo una ilusión? Alianza, Madrid, 1983.
Prigogine y Stengers: Entre el tiempo y la eternidad, Alianza, Madrid, 1991.
Nicolis y Prigogine: La estructura de lo complejo, Alianza, Madrid, 1994.
Prigogine, Ilya: El fin de las certidumbres, Andrés Bello, Santiago, Chile. 1996.
Prigogine, Ilya: Las leyes del caos, Drakontos, Crítica, Barcelona, 1997.