Wittgenstein, in the Tractatus, conceives the world as ‘the totality of facts’. Type-stratification threatens that conception : the totality of facts is an obvious example of an illegitimate totality. Wittgenstein’s notion of truthoperation evidently has some role to play in avoiding that threat, allowing propositions, and so facts, to constitute a single type. The paper seeks to explain that role in a way that integrates the ‘philosophical’ and ‘technical’ pressures on the notion of an operation.

I take as my text propostion 4.0312 of the Tractatus : The possibility of propositions is based on the principle that objects have signs as their representatives. My fundamental idea is that the ‘logical constants’ are not representatives; that there can be no representatives of the logic of facts. Practically the same words occur in Wittgenstein's Notebook for 25 December 1914, where Miss Anscombe translates them: The possibility of the proposition is, of course, founded on the principle of signs as (...) going proxy for objects. Thus in the proposition something has something else as its proxy. But there is also the common cement. My fundamental thought is that the logical constants are not proxies. That the logic of the fact cannot have anything as its proxy. (shrink)

Let me start with a well-known story. Kant held that logic and conceptual analysis alone cannot account for our knowledge of arithmetic: “however we might turn and twist our concepts, we could never, by the mere analysis of them, and without the aid of intuition, discover what is the sum [7+5]” (KrV, B16). Frege took himself to have shown that Kant was wrong about this. According to Frege’s logicist thesis, every arithmetical concept can be defined in purely logical terms, and (...) every theorem of arithmetic can be proved using only the basic laws of logic. Hence, Kant was wrong to think that our grasp of arithmetical concepts and our knowledge of arithmetical truth depend on an extralogical source—the pure intuition of time (Frege 1884, §89, §109). Arithmetic, properly understood, is just a part of logic. (shrink)

It is not immediately clear from Wittgenstein’s Tractatus how to connect his idea there of an object with the logical ontologies of Frege and Russell. Toward clarification on this matter, this paper compares Russell’s and Wittgenstein’s versions of the thesis of an atomic fact that it is a complex composition. The claim arrived at is that whilst Russell (at times at least) has one particular of the elements of a fact – the relation – responsible for the unity of the (...) whole, for Wittgenstein the unity of a fact is the product of copulative powers inherent in all its elements. All kinds of constituents of Tractarian facts – all kinds (forms) of object – are, to use Fregean terminology, unsaturated. (shrink)

It has been much debated whether Tractarian objects are what Russell would have called particulars or whether they include also properties and relations. This paper claims that the debate is misguided: there is no logical category such that Wittgenstein intended the reader of the Tractatus to understand his objects either as providing examples of or as not providing examples of that category. This is not to say that Wittgenstein set himself against the very idea of a logical category: quite the (...) contrary. However, where Russell presents his logical variety of particulars and the various types of universal, and Frege presents his of objects and the various types of function, Wittgenstein denies the propriety of such a priori expositions. Wittgenstein envisages a variety of logical types of entity but insists that the nature of these types is something to be discovered only through analysis. (shrink)

In his critical notice of Russell's Theory of Knowledge, R. E. Tully takes issue with my interpretation of Wittgenstein's criticism of Russell's theory of judgment. Against it he raises two objections and also sketches an alternative interpretation. On Tully's characterization, I believe that Russell was shot out of the tree by a subtle but devastating argument, while Tully believes that he was shaken out of the tree by a much broader but non-lethal attack on his conception of a proposition. The (...) metaphor is not inappropriate. I certainly believe that Wittgenstein's attack was lethal to Russell's theory of judgment and shows extraordinary marksmanship. But I do not want to deny that there was a lot of tree shaking going on at the same time—concerning, in particular, the logical constants and the concept of a proposition, both of which were topics closely related to the theory of judgment. Thus, while I maintain that Russell was shot, I do not subscribe to a single-bullet theory. (shrink)

The paper scrutinizes Frege's Euclideanism - his view of arithmetic and geometry as resting on a small number of self-evident axioms from which non-self-evident theorems can be proved. Frege's notions of self-evidence and axiom are discussed in some detail. Elements in Frege's position that are in apparent tension with his Euclideanism are considered - his introduction of axioms in The Basic Laws of Arithmetic through argument, his fallibilism about mathematical understanding, and his view that understanding is closely associated with inferential (...) abilities. The resolution of the tensions indicates that Frege maintained a sophisticated and challenging form of rationalism, one relevant to current epistemology and parts of the philosophy of mathematics. (shrink)

In the Tractatus Wittgenstein criticizes Frege and Russell's view that laws of inference (Schlussgesetze) "justify" logical inferences. What lies behind this criticism, I argue, is an attack on Frege and Russell's conceptions of logical entailment. In passing, I examine Russell's dispute with Bradley on the question whether all relations are "internal".

Frege's diatribes against psychologism have often been taken to imply that he thought that logic and thought have nothing to do with each other. I argue against this interpretation and attribute to Frege a view on which the two are tightly connected. The connection, however, derives not from logic's being founded on the empirical laws of thought but rather from thought's depending constitutively on the application to it of logic. I call this view 'psycho-logicism.'.