Feyerabend’s « The Concept of Intelligibility in Modern Physics » (1): against unknowability

Reading PHYSICS AND PHILOSOPHY, Feyerabend’s Philosophical Papers volume 4.

After a short introduction by Stefano Gattei and Joseph Agassi giving valuable historical context, the book begins with Feyerabend’s first known paper, « The Concept of Intelligibility in Modern Physics », which was published in 1948, when he was only 24 years old. The paper contains an argument for a realist interpretation of speculative physical theories and a critique of the doctrine of the « unknowability » of the real. It combines both ontological and epistemological considerations in a mutually reinforcing set of arguments.

The paper begins with a discussion of the impasses that arise in discussing our knowledge of the external world in terms of

the pair of concepts, real external world/phenomenon, which represents our difficulty in philosophical terms (page 4).

Feyerabend proposes to replace this problematic pair of concepts with a potentially more fruitful pair, that of « intelligible/abstract ». However, this second pair seems to determine a sharp opposition, and to lead equally to an impasse, as what is abstract is often taken as less intelligible, and therefore less real, than more concrete processes and objects.

To overcome this problem, Feyerabend embarks on a consideration of the relation between simple visual models and the notion of intelligibility.

in the natural sciences, we have always sought to resolve all phenomena available to the senses into simple visual models, and in so doing to make the mechanism intelligible. Such models explain macroscopic regularity, but do not themselves require further explanation. They are immediately clear, evident, vivid (4).

Concrete and abstract, on this view, are not objective properties of our theoretical models, but represent evaluations of such models based on their degree of familiarity. In other words, they are historical concepts.

Note: we can see here already, in 1948, Feyerabend’s tendency to replace timeless essences with concepts whose application varies over time, and that need to be treated according to an historical approach. This historical approach is associated, as in his later work, with a realist interpretation of theories. One surprising feature of the text is that Feyerabend calls this realist historical approach « positivism », whereas usually he associates this term with the opposite approach based on a-historical abstractions.

To explicate the standard concept of intelligibility, Feyerabend remarks that it corresponds to that of « vividness ». Yet vividness proves to be a complex notion, as it refers not only to a model that can readily be pictured on the basis of our immediate experience, but also to a model that can be pictured in terms of an entrenched theory that is felt to be immediately comprehensible. In both cases intelligibility is derived from familiarity.

On the standard view the intelligibility of later more abstract theories is held to depend on their resemblance to the familiar pictures we have elaborated to make sense of the objects and processes of our immediate environment and of the laws that govern their behaviour. However, Feyerabend argues against the conservativism of attempting to use present intelligibility as a criterion of acceptability of theories.

Thus a plausible theory is one that permits a « vivid rendition »:

In the case of Greek atomists, such a vivid rendition presupposes, quite primitively, that everything that happens can be traced back to collisions; whereas in the case of classical mechanics, to the motion of attracting masses. In the one case, it is a model that became plausible through the behavior of things in the immediate environment; in the other, it is a conception that comes from the regularity of planetary orbits, which was already understood (4).

Feyerabend remarks that the model of classical mechanics, which now seems so clear and evident as to be a model of intelligibility, was initially considered to be very problematic as it contained the assumption of an occult force proceding by action at a distance, which was thought to be not only implausible but unintelligible, « incomprehensible,  absurd ». The charge of absurdity, however, is no objection against the power of a theory to describe the real, and amounts only to declaring that the theory is currently unfamiliar and difficult to picture.

Laplace’s theory of capillary pressure is the best example of the extent to which the concept of intelligibility is subject to change, and how little the failure to picture a theory can be used as an argument against its content (5).

The logical conclusion is that seemingly unintelligible theories, such as relativity and quantum theory, can become intelligible if we are willing to revise our pictures and to familiarise ourselves with the new ones.There is no reason to give a realist interpretation to only to familiar theories such as atomism and classical mechanics, but to impose an instrumentalist interpretation for relativity and quantum mechanics.

But if we have successfully removed the requirement of « vivid rendition » as a condition for the intellgibility of a theory, then we have undone the equation between picturability and knowability. This means that the argument to the unknowability of the real, founded on the use of « unpicturable » theories (relativity, quantum theory), fails. These theories are not mere tools to predict and manipulate phenomena, but are means of knowing the real.

This problem of the real world versus phenomenal worlds, and that of the spectre of instrumentalism, are with us still. Graham Harman’s object-oriented philosophy gives an instrumentalist interpretation of science, the humanities, and even of common sense. On this view, science does not give us ontological knowledge of real objects and relations, but only instrumental knowledge of sensual worlds. The argument turns around the same aporia as 70 years ago: if it can’t be pictured it can’t be known, if it can be pictured it can’t be real. Feyerabend, at the age of 24, already saw through the primitivism that underlies this pessimistic ontology and refuted its presuppositions.

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