The Concept of Logic in Wittgenstein's Tractatus

Abstract

Although talk about the "ontology" of the Tractatus is quite common, Wittgenstein
himself, in a certain sense, seems to regard the sentences of the Tractatus as
sentences of logic. For example, in 2.012-2.0121, where he sets forth the theory of
internal properties of objects, he points out that, "in logic", nothing can be by
chance. Again, in 6.22 he talks about the "logic of the world", and in 6.12 about the
"formal - logical properties of the world". Similarly, in the Notebooks 1914-1916, he
regards the question of the existence of simple objects as something that can be
answered "in LOGIC" (9.5.1915). This could mean, as several interpreters have
thought, that ontological concepts playing a central role in the Tractatus, such as
'object' or 'state of affairs', could be defined in purely logical terms. The
Tractatus ontology, then, would be reducible to logic. In this paper I propose
another interpretation of Wittgenstein's conception of logic. According to my
interpretation, logical and ontological concepts in the Tractatus are mutually
dependent on each other: Neither can ontological concepts be defined without logical
concepts nor logical concepts without ontological ones. Nevertheless, the ontological
aspects of the Tractatus are restricted to purely formal and in this sense "logical"
properties of reality. It is this restriction that makes the ontological aspects a
genuine part of logic in the sense of the Tractatus.