The Philosophical Investigations was the major expression of Wittgenstein's later philosophy, and directly argued against many of the ideas he had first proposed in his Tractatus Logico-Philosophicus . In the Tractatus , Wittgenstein wrote terse, axiomatic and almost mathematical propositions which argued that
language had a fundamental, logical connection to reality and that words gained
meaning by functioning as representations which combine to form logical pictures of how the world might be. In the Investigations , Wittgenstein changes his position, and begins to see language as an independent force which
contains the potential for meaning and communication
simply because in speaking to one another, humans participate in a kind of 'language
game' in which sense is made by adhering to the rules and conventions. He sees language as made up of countless games and conventions, from asking the
time to being interviewed for a job. He rejects the need to distill language into some unified formula. In fact, behind the Investigations is a profound distrust in treating philosophical issues in a scientific manner, and of trying to get 'underneath' language in the way a scientist may get underneath puzzles of space and time. The truth, as far as language is concerned, is on the surface. Meaning wears its heart on its sleeve, one might say. Language is not a problem to be solved, but a phenemena to describe.
There is still in his
thoughts a preoccupation with the relationship between language and religion or metaphysics, or more specifically our inability to validly speak metaphysically. He claims that language has meaning when used in the convention of game(s) in which we employ it, but sometimes we can take words out of their meaningful context and use them in ways that they are not suited to. However, because of the seeming coherence of grammatically valid statements, these instances of language abuse can pass for sensible communications of truth. For instance, words like 'substance' or 'time' only really have meaning in instances of the specific i.e. this substance, or what is the time. If we simply ask 'what is time?' is seems that we have raised a valid question. This validity is an illusion. It is simply an example of a word being used out of its context or 'language game' and thus out of its depth.
The Investigations also contains lengthy discourse concerning the infamous 'private language' argument, in which Witgenstein strengthens his argument for the communicative, social nature of language and meaning (as opposed to the axiomatic, pseudo-scientific model) by claiming that it would be impossible for an individual to have a 'private' language divorced from the experiences of which it speaks, and the presence of other people to be spoken to. There are other parts of his overall argument, but that mentioned is the the crux of the case.
The style of the book is similarly informal, composed of observations and thoughts, often digressing and returning only to digress again. In the introductory note, Wittgenstein says that although he tried to impose a hard form and sequence to his arguments, the thoughts which comprised them did not allow themselves to be framed. Again, this is notably different from the Tractatus; a bafflingly rigorous text in which he imposed the most stringent shape on the progress of the theories.
On the whole, the Investigations is a more sound philosophical position that the Tractatus . It is ingenious in the manners in which it notes the tendencies of philosphers to unify, to distil, and the effect that this has on their arguments. He asks what this unification is exactly, and why should issues be distilled? Why should they not be precisely as they are? In the process of distillation, we take language away from its actual, pragmatic use and make it something precious, something unnaturally pure. Tleads philosophers into meaningless dialogue. It makes it necessary to build complex arguments which he likens to a spiders web and after a while each new part of the web is just deflecting criticisms and trying to strengthen the web as a whole, completely forgetting the original issue, the original conjecture.
Wittgenstein's main preoccupation in both texts is the setting of limits to discourse, and the untangling of confusion which results from not seeing the actual nature of language. The Tractatus and the Investigations are not, therefore, completely incongruent texts, since they both represent an attempt to prevent philosophy running into blind alleys and whirlpools whose most dangerous characteristic is their apparent coherance.
The Investigstions is not an easy book to understand, and also makes more sense when held up against his earlier work, and one would be strongly advised to read widely around the secondary literature. However, he is a philosopher well worthy studying with for his writing contains great power, elegance and beauty.