ABSTRACT
One important difference between the notions of substance and knowledge is that 'substance' is a philosophical term of art and a term, as they used to say, of 'second intention', connoting logical and ontological status. Moreover, it may seem evident that, since different philosophers have used the word in different ways, there is no correct way of using it, and so no truth about 'substance' to be uncovered by reflection on its use. Yet its admittedly rather varied employment has been part of a sustained attempt to understand (if also sometimes to improve) fundamental ways of thinking which are not only familiar to us, but which penetrate to the deep structure of language. The automatic hostility with which the traditional notion is liable to be received by present-day philosophers has disparate sources. The empiricist's horror of supposed unknowables is now, perhaps, less fashionable than the neo-idealist or conceptualist dislike of explanations of specific logical form which present it as other than arbitrary, mutable and at best useful. Another important motive is the feeling that modern physics has undermined the claims to ultimacy inherent in the substance-based ontologies of the past, just as (it is supposed) any currently preferred ontology is in turn vulnerable to future physics. The aim of the present section is to show how traditional realist doctrines of substance, suitably interpreted, have an explanatory force which pragmatism or any other form of conceptualism cannot hope to match. The explanations it supplies are of primitive structural features of our thinking to which
considerations drawn from the philosophy of physics are simply irrelevant.
