The philosopher Ludwig Wittgenstein produced two highly original systems of philosophy. Both of them had as its aim to study the structure and limits of human thought by looking at the structure and limits of language.
His first major system was expounded in the Tractatus Logico-Philosophicus; in it, he sought to fence off the things about which something could be said from those in which something could not be said. He did this by examining the nature of a thing that could be talked about. He supposed that if language could be used when talking about a thing, then we should be able to create a concrete picture of that thing that shares somehow the logical form of that thing. (I say 'somehow'; Wittgenstein talked in the Tractatus about how the relationship between the thing and its picture is one of the things that couldnt be talked about - they could be 'shown' but not 'said') Each fact that had logical sense (i.e that created a concrete picture in our minds) therefore had a sentence that could be broken into basic propositions connected together with 'and', 'or' and 'not'. And everything that could be talked about could be built out of this collection of basic propositions. Religion, ethics and aesthetics were not in the collection; they were things that could only be shown. This approach fenced religion off from any claims by science or logic to prove or disprove things in its domain.
Wittgenstein actually thought he had found and answer to philosophy, and so he took a lengthy hiatus from the subject. However, the Tractatus had a rigid view of reality as determining language; what if the language we used influenced what we percieved as being reality? In this regard, he was very influenced by reading The Golden Bough, by James Frazier, one of the first attempts to describe how different cultures view reality. In the Tractatus, the assumption was that all languages had a common structure, but Wittgenstein realised it was actually quite hard to give a single definition which covered all the different things which we term as a 'language'.
Wittgenstein's second philosophy is mainly dealt with in Philosophical Investigations, which was published after his death. In it, Wittgenstein proposes that a word has meaning not because of a definition which ties a word to that singular meaning; instead a word has meaning based on the context in which it is used. Using the classic example of the word 'game', Wittgenstein showed it would be impossible to come up with a definition, but that doesn't stop us from using the word successfully, because we are able to intuitively know what is a game and what is not. Wittgenstein argued this intuition is formed by culture and society, and that hence one's thoughts could not exist independently of the social context in which they were formed.
Wittgenstein contends that philosophical problems arise when language is taken out of the context in which it functions perfectly in daily life. The role of the philosopher, then, is to point out where language has 'gone on holiday' (in other words been forced in to metaphysical contexts) so that it can be returned to the context in which it is used in daily life. The very structure of language is such that it easily sets one on the road to confusion, and most of Philosophical Investigations is spent with close examination of different uses of language, sometimes in a dialogue between Wittgenstein and a 'puzzled' philosopher who has to be shown the way out of the maze. This later philosophy of Wittgenstein's has had a major impact outside philosophy, and has inspired new approaches in the fields of psychology and anthropology.
