Daqiang Li

This article focuses on several important but obscure concepts in Tractatus Logico-Philosophicus. In order to clarify the concept of “object”, I compare it with “atom”. The analysis of the two concepts explains two important questions which have confused Wittgenstein’s reviewers for long: why is the world not the totality of things? Is object substance? “Logical space” is an important concept in Tractatus Logico-Philosophicus, although it only appears several times. If a proposition serves as the coordinates in the logical space, what are the coordinate axes? Is a possible world a point in the logical space, or a set of points in it? Based on symbolic transformations, I suggest that possible worlds serve as coordinate axes in the logical space. The concept of “possible worlds” contradicts with “necessity”. In Wittgenstein’s theory, all possible worlds are “accessible” to one another. This is why Wittgenstein fails to cope with the conflict between “possibility” and “necessity”.

Is the statue made of copper identical with the piece of copper from which it is made? This question was argued for years since Allan Gibbard published Contingent Identity in 1975. Before arguing for or against identity, I try to clarify different usages of the word “identity” and the conditions under which Leibniz’s Law is effective. In our language, there are four concepts of identity, and Leibniz’s Law works differently in each case. Both monist and pluralists fail to distinguish the four concepts. However, monist could be right.