From owner-bhaskar Mon Aug 5 17:43:25 1996 Date: Mon, 5 Aug 1996 15:38:59 -0600 Message-Id: <> From: Hans Ehrbar <> Subject: rts2-12 24 A Realist Theory of Sciencen 2. THREE TRADITIONS IN THE PHILOSOPHY OF SCIENCE Viewed historically, three broad positions in the philosophy of science may be distinguished. According to the first, that of *classical empiricism*, represented by Hume and his heirs, the ultimate objects of knowledge are atomistic events. Such events constitute given facts and their conjunctions exhaust the objective content of our idea of natural necessity. Knowledge and the world may be viewed as surfaces whose points are in isomorphic Philosophy and Scientific Realism 25 correspondence or, in the case of phenomenalism, actually fused. On this conception, science is conceived as a kind of automatic or behavioural response to the stimulus of given facts and their conjunctions. Even if, as in logical empiricism, such a behaviourism is rejected as an account of the genesis of scientific knowledge, its valid content can still in principle be reduced to such facts and their conjunctions. Thus science becomes a kind of epiphenomenon of nature. The second position received its classical though static formulation in Kant's *transcendental idealism*, but it is susceptible of updated and dynamized variations. According to it, the objects of scientific knowledge are models, ideals of natural order etc. Such objects are artificial constructs and though they may be independent of particular men, they are not independent of men or human activity in general. On this conception, a constant conjunction of events is insufficient, though it is still necessary, for the attribution of natural necessity. Knowledge is seen as a structure rather than a surface. But the natural world becomes a construction of the human mind or, in its modern versions, of the scientific community. The third position, which is advanced here, may be characterized as *transcendental realism*. It regards the objects of knowledge as the structures and mechanisms that generate phenomena; and the knowledge as produced in the social activity of science. These objects are neither phenomena (empiricism) nor human constructs imposed upon the phenomena (idealism), but real structures which endure and operate independently of our knowledge, our experience and the conditions which allow us access to them. Against empiricism, the objects of knowledge are structures, not events; against idealism, they are intransitive (in the sense defined). On this conception, a constant conjunction of events is no more a necessary than it is a sufficient condition for the assumption of the operation of a causal law. According to this view, both knowledge and the world are structured, both are differentiated and changing; the latter exists independently of the former (though not our knowledge of this fact); and experiences and the things and causal laws to which it affords us access are normally out of phase with one another. On this view, science is not an epiphenomenon of nature, nor is nature a product of man. 26 A Realist Theory of Science A word of caution is necessary here. In outlining these positions, I am not offering them as a complete typology, but only as one which will be of some significance in illuminating current issues in the philosophy of science. Thus I am not concerned with rationalism as such, or absolute idealism. Moreover, few, if any, modern philosophers of science could be unambiguously located under one of these banners. Nagel for example stands somewhere along the continuum between Humean empiricism and neo-Kantianism; Sellars nearer the position characterized here as transcendental realist; and so on. One could say of such philosophers that they combine, and when successful in an original way synthesize, aspects of those philosophical limits whose study we are undertaking. It is my intention here, in working out the implications of a full and consistent realism, to describe such a limit; in rather the way Hume did. As an intellectual exercise alone this would be rewarding, but I believe, and hope to show, that it is also the only postion that can do justice to science. Transcendental realism must be distinguished from, and is in direct opposition to, *empirical realism*. This is a doctrine to which both classical empiricism and transcendental idealism subscribe. My reasons for rejecting it will be elaborated in a moment. `Realism' is normally associated by philosophers with positions in the theory of perception or the theory of universals. In the former case the real entity concerned is some particular object of perception; in the latter case some general feature or property of the world. The `real entities' the transcendental realist is concerned with are the objects of scientific discovery and investigation, such as causal laws. Realism about such entities will be seen to entail particular realist positions in the theory of perception and universals, but not to be reducible to them. Only transcendental realism, I will argue, can sustain the idea of a law-governed world independent of man; and it is this concept, I will argue, that is necessary to understand science. Classical empiricism can sustain neither transitive nor intransitive dimensions; so that it fails both the criteria of adequacy (1)' and (2)' advanced on page 24 above. Moreover in its most consistent forms it involves both solipsism and phenomenalism; so that neither (1) nor (2) can be upheld. In particular Philosophy and Scientific Realism 27 not even the idea of the independence of the event from the experience that grounds it, i.e. the intransitivity of events, can be sustained; and, in the last instance, events must be analysed as sensations or in terms of what is epistemologically equivalent, viz. human operations. Transcendental idealism attempts to uphold the objectivity (intersubjectivity) of facts, i.e. (1). And, if given a dynamic gloss, it can allow a transitive dimensions and satisfy criterion (1)'; so that, in this respect, it is an improvement on empiricism. According to such a dynamized transcendental idealism knowledge is given structure by a sequence of models, rather than a fixed set of a priori rules. However in neither its static nor its dynamic form can it sustain the intransitive dimension. For in both cases the objects of which knowledge is obtained do not exist independently of human activity in general. And if there are things which do (things-in-themselves), no scientific knowledge of them can be obtained. Both transcendental realism and transcendental idealism reject the empiricist account of science, according to which its valid content is exhausted by atomistic facts and their conjunctions. Both agree that there could be no knowledge without the social activity of science. They disagree over whether in this case there would be no nature also. Transcendental realism argues that it is necessary to assume for the intelligibility of science that the order discovered in nature exists independently of men, i.e. of human activity in general. Transcendental idealism maintains that this order is actually imposed by men in their cognitive activity. Their differences should thus be clear. According to transcendental realism, if there were no science there would still be a nature, and it is this nature which is investigated by science. Whatever is discovered in nature must be expressed in thought, but the structures and constitutions and causal laws discovered in nature do not depend upon thought. Moreover, the transcendental realist argues, this is not just a dogmatic metaphysical belief; but rather a philosophical position presupposed by key aspects of the social activity of science, whose intelligibility the transcendental idealist cannot thus, anymore than the empiricist, sustain. Neither classical empiricism nor transcendental idealism can sustain the idea of the independent existence and action of the 28 A Realist Theory of Science causal structures and things investigated and discovered by science. It is in their shared ontology that the source of this common incapacity lies. For although transcendental idealism rejects the empiricist account of science, it tacitly takes over the empiricist account of being. This ontological legacy is expressed most succintly in its commitment to empirical realism, and thus to the concept of the `*empirical world*'. For the transcendental realist this concept embodies a sequence of related philosophical mistakes. The first consists in the use of the category of experience to define the world. This involves giving what is in effect a particular epistemological concept a general ontological function. The second consists in the view that it's being experienced or experienciable is an essential property of the world; whereas it is more correctly conceived as an accidental property of some things, albeit one which can, in special circumstances, be of great significance for science. The third thus consists in the neglect of the (socially produced) circumstances under which experience is in fact epistemically significant in science. If the bounds of the real and the empirical are co-extensive then of course any `surplus-element' which the transcendental idealist finds in the analysis of law-like statements cannot reflect a real difference between necessary and accidental sequences of events. It merely reflects a difference in men's attitude to them. Saying that light travels in straight lines ceases then to express a proposition about the world; it expresses instead a proposition about the way men understand it. Structure becomes a function of human needs; it is denied a place in the world of things. But just because of this, I shall argue, the transcendental idealist cannot adequately describe the principles according to which our theories are constructed and empirically tested; so that the rationality of the transitive process of science, in which our knowledge of the world is continually extended and corrected, cannot be sustained. To say that the weaknesses of both the empiricist and idealist traditions lie in their commitment to empirical realism is of course to commit oneself to the impossibility of ontological neutrality in an account of science; and thus to the impossibility of avoiding ontological questions in the philosophy of science. The sense in which every account of science presupposes an ontology is the sense in which it presupposes a schematic Philosophy and Scientific Realism 29 answer to the question of what the world must be like for science to be possible. Thus suppose a philosopher holds, as both empiricists and transcendental idealists do, that a constant conjunction of events apprehended in sense-experience is at least a necessary condition for the ascription of a causal law and that it is an essential part of the job of science to discover them. Such a philosopher is then committed to the belief that, given that science occurs, there are such conjunctions. As Mill put it, that `there are such things in nature as parallel cases; that what happens once will, under a sufficient degree of similarity of circumstance, happen again'.7 There are two important points to register about such ontological beliefs and commitments. The first is that they should only be interpreted hypothetically, viz. as entailing what must be the case for science to be possible; on which interpretation it is a contingent fact that the world is such that science can occur. It is only in this relative or conditional sense that an account of science presupposes an ontology. The status of propositions in ontology may thus be described by the following formula: It is not necessary that science occurs. But given that it does, it is necessary that the world is a certain way. It is contingent that the world is such that science is possible. And, given that it is possible, it is contingent upon the satisfaction of certain social conditions that science in fact occurs. But given that science does or could occur, the world *must* be a certain way. Thus, the transcendental realist asserts, that the world is structured and differentiated can be established by philosophical argument; though the particular structures it contains and the ways in which it is differentiated are matters for substantive scientific investigation. The necessity for categorical distinctions between structures and events and between open systems and closed are indices of the stratification and differentiation of the world, i.e. of the transcendental realist philosophical ontology. These distinctions are presupposed, it will be shown, by the intelligibility of experimental activity. Whenever there is any danger of confusion between an `ontology' in the sense of the kind of world presupposed by a philosophical account of science and in the sense of the particular entities and processes postulated by some 7 J. S. Mill, A System of Logic, Bk. III, Chap. 3, Sect. 1. 30 A Realist Theory of Science substantive scientific theory I shall explicitly distinguish between a philosophical and a scientific ontology. The second point to stress is that propositions in ontology cannot be established independently of an account of science. On the contrary, they can only be established by reference to such an account, or at least to an account of certain scientific activities. However, it will be contended that this essential order of analysis, viz. science --> being, *reverses* the real nature of dependency (or, we could say, the real burden of contingency). For it is not the fact that science occurs that gives the world a structure such that it can be known by men. Rather, it is the fact that the world has such a structure that makes science, whether or not it actually occurs, possible. That is to say, it is not the character of science that imposes a determinate pattern or order on the world; but the order of the world that, under certain determinate conditions, makes possible the cluster of activities we call `science'. It does not follow from the fact that the nature of the world can only be *known* from (a study of) science, that its nature is *determined* by (the structure of) science. Propositions in ontology, i.e. about being, can only be established by reference to science. But this does not mean that they are disguised, veiled or otherwise elliptical propositions about science. What I shall characterize in a moment as the `*epistemic fallacy*' consists in assuming that, or arguing as if, they are. .