Charles Sayward

The idea underlying the Begriffsschrift account of identities was that the content of a sentence is a function of the things it is about. If so, then if an identity a=b is about the content of its contained terms and is true, then a=a and a=b have the same content. But they do not have the same content; so, Frege concluded, identities are not about the contents of their contained terms. The way Frege regarded the matter is that in an identity the terms flanking the symbol for identity do not have their ordinary contents, but instead have themselves as their contents. In ?Uber Sinn und Bedeutung? Frege became convinced that if an identity a=bis about the signs aand b, then it expresses no proper knowledge. So, since it is evident that many such identities do express proper knowledge, Frege concluded that identities are not about their contained signs. So he became convinced that his Begriffsschrift account was incorrect. What was the error in the argument that led Frege to that account? It was thinking that the content of a sentence is a function of the contents of its constituent signs, that is, the things it is about

In this book a non-realist philosophy of mathematics is presented. Two ideas are essential to its conception. These ideas are (i) that pure mathematics--taken in isolation from the use of mathematical signs in empirical judgement--is an activity for which a formalist account is roughly correct, and (ii) that mathematical signs nonetheless have a sense, but only in and through belonging to a system of signs with empirical application. This conception is argued by the two authors and is critically discussed by three philosophers of mathematics.

Consider the general proposition that normally when people pain-behave they are in pain. Where a traditional philosopher like Mill tries to give an empirical proof of this proposition (the argument from analogy), Malcolm tries to give a transcendental proof. Malcolm’s argument is transcendental in that he tries to show that the very conditions under which we can have a concept provide for the application of the concept and the knowledge that the concept is truly as well as properly applied. The natural basis for applying the concept of pain to someone else is pain-behavior like groaning and crying out. To know that a person pain-behaving is in pain is to rule out countervailing circumstances (smiles, exaggerated cries, winks, absence of plausible cause, and so on). The basic move by Malcolm is to make these special conditions a function merely of the concept of pain.

One of the things C. D Broad argued many years ago is that certain 'scientific' arguments against dualist interactionism come back in the end to a metaphysical bias in favor of materialism. Here the authors pursue this basic strategy against another 'scientific' argument against dualism itself. The argument is called 'the argument from continuity'. According to this argument the fact that organisms and species develop by insensible gradations renders dualism implausible. The authors try to demonstrate that this argument fails to establish the implausibility of dualism.

Four views of arithmetical truth are distinguished: the classical view, the provability view, the extended provability view, the criterial view. The main problem with the first is the ontology it requires one to accept. Two anti-realist views are the two provability views. The first of these is judged to be preferable. However, it requires a non-trivial account of the provability of axioms. The criterial view is gotten from remarks Wittgenstein makes in Tractatus 6.2-6.22 . It is judged to be the best of four views. It is also defended against objections.

Let C1 and C2 be distinct moral codes formulated in English. Let C1 contain a norm N and C2 its negation. The paper construes the moral relativist as saying that if both codes are consistent, then, in the strongest sense of correctness applicable to moral norms, they are also both correct in the sense that they contain only correct moral norms. If we believe that the physical statements of English are true (false) in English, we will reject an analogous statement made of physical theories. We will hold that the strongest sense of correctness applicable to physical statements is not system-relative. The moral relativist denies that there is any corresponding sense of correctness applicable to moral norms. That is, there is no notion of moral correctness that is not system-dependent. It is argued that, while the position may not be true, there is not a strictly logical basis for refuting it.

Suppose there is a domain of discourse of English, then everything of which any predicate is true is a member of that domain. If English has a domain of discourse, then, since ‘is a domain of discourse of English’ is itself a predicate of English and true of that domain, that domain is a member of itself. But nothing is a member of itself. Thus English has no domain of discourse. We defend this argument and go on to argue to the same conclusion without relying on the supposition that English is a language which contains the predicate ‘is a domain of discourse of English’.