In 1934 when Gaston Bachelard published his Nouvel Esprit Scientifiquefootnote1 and Karl Popper’s Logik der Forschungfootnote2 appeared few philosophers would have dissented from the view that science develops in a linear or monistic fashion, so as to leave meaning and truth-value unchanged, on the basis provided by common experience. Meyerson had even undertaken to show that the theory of relativity could be deduced from Newtonian principlesfootnote3 and it was widely held that, for their part, the concepts of classical physics were just a refinement of the concepts of daily life.footnote4 Since then Bachelard, in France, and Popper, in England, have been more than any others responsible for the seeping into the general philosophical consciousness (which includes the consciousness of scientists in their reflection upon their work) of the fact, profoundly revolutionary for philosophy, of the phenomenon of scientific discontinuity (with respect to common sense or experience) and change. In strikingly similar terms Bachelard and Popper attempted to register this phenomenon. Yet neither of them, nor the theoretical traditions they inaugurated, have succeeded in grasping its full significance for philosophy. Dominique Lecourt’s Marxism and Epistemologyfootnote5 and Paul Feyerabend’s Against Methodfootnote6 constitute in a sense extended commentaries on these traditions and their attempts to theorize scientific discontinuity and change—the one, a respectful tribute ‘from outside’; the other, a ‘wicked’ polemic from within.

Why do scientific discontinuity and change have such disturbing consequences for philosophy? Their recognition snaps the privileged relationship between subject and object which, in classical philosophy, uniquely ties thought to things. Thought cannot now be viewed as a mechanical function of given objects (as in empiricism); nor can the activity of creative subjects be regarded as endowing the world with things (as in idealism); nor is any combination of the two possible. In short, it becomes necessary to distinguish clearly between the unchanging real objects that exist outside the scientific process and the changing cognitive objects that are produced within science as a function of scientific practice. Let me call the former intransitive and the latter transitive objects; the theoretical space in which to talk about them will accordingly become the intransitive and transitive dimensions respectively of the philosophy of science.

I now want to put forward the following theses: Any adequate account of science depends upon the explicit recognition of the necessity for both, and the non-identity of the objects of, the intransitive and transitive dimensions. The history of philosophy is, on the other hand, characterized by persistent attempts to reduce one to the other. These attempts are necessarily unsuccessful so that they result merely in the generation of an implicit or disguised ontology (in the intransitive dimension) or sociology (in the transitive one). But the attempt to do so secures the dominance in philosophy of an empiricist ontology and an individualist sociology; and it is in this attempt and its results that the ideological value of classical philosophy lies. An adequate account of science depends, by contrast, upon the development of an explicit non-empiricist ontology and a non-individualist conception of scientific activity (or sociology, in the special sense of the word I am using here).footnote7

Now in the operation empiricist ontology = individualist sociology that structures classical philosophy typically, at least, it is knowledge and its subject, man, that plays the leading role. Thus it may be the need expressed for certain foundations for knowledge that results in the establishment of the implicit empiricist ontology—a process covered by the collapse of the concept of an intransitive dimension in the philosophy of science (that is, by the denial of the need for an ontology). Consider, for example, the empiricist variant dominant at the time Bachelard wrote The New Scientific Mind and Popper wrote The Logic of Scientific Discovery. In response to the question posed by scepticism, knowledge is restricted to what is known for certain; it is then shown, in a phenomenalistic analysis of perception, that what is known in perception is certain; only perception gives knowledge of things (principle of empiricism); hence knowledge must be of what is given in perception. Thus on the one hand only items directly given in sense-experience may be said to be known to exist; and, on the other, the world may now, from the point of view of epistemology, be regarded as constituted by facts which are as given as the real objects of perception and certain as a result of the analysis which identifies them with the latter. In this way facts, which are social products, stand in, in philosophy, for the particulars of the world and there is no need to bother with the question of whether things exist independently of them. It should be noted that ontology is denied while being presupposed. For, of course, it must be assumed that the world is such that it could be the object of such a cognitive operation of man. And, in particular, it is presupposed that it consists of discrete atomistic events or states-of-affairs, the ontological surrogates of the knowledge-constituting experiences, revealing an invariant order of coexistence in space and succession over time. As a result of this operation scientific knowledge becomes as certain as what exists and as commonplace as the activity (perception) that establishes it. The question—of scepticism—which initiates the philosophical play must be posed so that philosophy can give the answer its function demands.

The immediate ideological effects, in the transitive dimension, of this operation are clear. Scientific knowledge is certain, its development is monistic. At the same time it is safe, it does not threaten the spontaneous consciousness of ordinary life (for it is built up out of units available to it). Thus we have both an ideology for science and an ideology of science: the former constituting beliefs rationalizing the scientific status quo, in Kuhn’s terminology, the practice of ‘normal science’;footnote8 the latter constituting beliefs about science, rationalizing the wider social status quo, bourgeois society as such. But this operation has ideological effects, though less obvious ones, in the intransitive dimension too.

Once we break the privileged relationship between subject and object and clearly distinguish between the transitive and intransitive dimensions of the philosophy of science, as we must once we register the discontinuities of scientific knowledge both over time and with respect to common experience, ‘scientific knowledge’ ceases to be an essential property of either person or things: it becomes something distinctive, with a site (and worth a study) of its own, bearing relations which are contingent and problematic to both. Now neither Bachelard nor Feyerabend have a concept of the intransitive dimension of the philosophy of science, they are both still committed to an essentially empiricist ontology. Moreover, in both cases their accounts of the transitive dimension are marred by individualistic deformations (in Bachelard’s case, psychologistic, in Feyerabend’s, voluntaristic). These are, I intend to show, the fundamental weaknesses of their philosophical positions. It is because of this continuing commitment to an empiricist ontology and an (at least residually individualist) sociology that, though their work marks, in different respects, a great advance on the past, neither of them is capable of providing us with the philosophy that science deserves, and that social science—inescapably—needs.

The most important influence on Feyerabend has been Karl Popper, and to understand his philosophy one must go back to the Vienna of the 1920s where he was a student. As Popper puts it, ‘there had been a revolution in Austria: the air was full of revolutionary slogans and ideas, and new and often wild theories’—Einstein’s theory of relativity, Marx’s theory of history, Freud’s psycho-analysis and Adler’s ‘individual psychology’.footnote9 In this context a group of philosophers, whose leading members were Carnap, Neurath and Schlick, tried to work out a criterion for distinguishing genuinely scientific from non-scientific (or ‘metaphysical’) propositions. Much influenced by Wittgenstein, they constructed a system, logical positivism—in essence a restatement of Machian empiricism in a form made possible by the development of Russelian logic—according to which our knowledge of the world could be reconstructed from elementary propositions expressed in sense-experience. Scientific propositions were about the world, known in sense-experience; if a sentence did not refer directly or indirectly to sense-experience, that is if no possible observation was relevant to the determination of its truth-value, then it was unscientific and, according to the logical positivists, meaningless. Attempting to formulate a criterion which would show propositions actually accepted in science to be justified, and not unreasonably assuming that science could know at least some propositions to be true (i.e. that it possessed some positive knowledge), they formulated their criterion for the demarcation of scientific from non-scientific propositions in terms of the verifiability (i.e. susceptibility to positive test) of the former.