These studies and the work they gave rise to, Philosophical Investigations, are commonly understood as a refutation of the author's previous major work, Tractatus Logic-Philosophic us. I didn't read the Blue and Brown Books as a refutation, as much as a correction, of the system of thought at work in the Tractatus.
That earlier work, as I read it, contained some troublingly bizarre implications and assumptions. It at times seemed to me that Wittgenstein was implying that linguistic information, being understood, could not be refuted- as if our ideas about things never change, or as if a statement could never be doubted- as if lying (on one hand) or misunderstanding (on the other) were not common occurrences, and if we shouldn't then, take such situations into consideration when interrogating the nature of communication and knowledge. The Blue and Brown Books brilliantly address such concerns about the line of thought at work in the Tractatus.
If we are to understand the workings of language, Wittgenstein argues, we must not ask “what does 'x' mean?” but rather “how does 'x' mean?” Signs, Wittgenstein asserts, can only operate according to the rules a linguistic system imposes. Unfortunately, the rules of our grammar have the effect of misleading us as to language's real nature. Our grammar constantly operates metaphorically. The metaphors are so omni-present that we speakers have come to take them as literal identifiers. The statement “I think of 'x',” implies that the sign is a translation of something in our heads that exists analogously to the sign. We users of language are thus led to believe there must be an intermediary step between thought and expression.
Thus, grammar leads us to believe that we can apply a term such as “similar” to what our very language designates as different. To use a simple example, Wittgenstein points out that what language designates as “different” colors- torqouis, ocean, blue-green, are commonly considered “similar” in that they are sub-categories of “blue.” This implies that there is a unifying concept of “blue” that exists in thought prior to expression. Language then, seeks to express the “thought”- the static, abstract truth that precedes it, and this manifests itself in the metaphysical impulse in philosophy.
In place of this inherently futile project, Wittgenstein prescribes replacing our concept of “thought” with the expression itself, the sign. Our statements, rather than attempts to give socialized form to some inner, spiritual truth, some inference to knowledge, are rather descriptions of knowledge. Words describe what can be known by revealing themselves. Of course, words have no concrete, changeless meaning. They demonstrate their meaning within their contextual use, just as the move of a chess piece across a board has one special significance within its context within an individual match. Thought, the use of language, can describe the way it functions but it can never explain why it functions the way that it does.
The question remains, however, how language, which demonstrates its functionality through its very implementation, can be used to intentionally mislead about things other than its own nature. Wittgenstein's radical response is that lying isn't altogether possible in the sense of completely misleading another person. A lye never completely misleads precisely because it is understood by the addressee, whether or not the addressee believes the statement to be true. No matter what the speaker's intention, they have necessarily revealed themselves to the addressee through the gesture of meaning that they perform. The speaker has made her/his “move.” To truly mislead the addressee, the speaker would have to adopt a private language- another inherently self-defeating project.
Still, the fact remains that the term “lying” can be successfully implemented. What can we be referring to by describing a statement as a lye other than the way we feel when we make a statement we consider to be “untrue” as opposed to what we feel when we make a statement we consider to be “true”? Such feelings, and the gestures and tonalities that sometimes accompany them, Wittgenstein calls “modes of expression.” But these “feelings” these “truths behind the lies” can only be conveyed through more words. What, then, of the private- the emotional and sentimental? Where is their place in thought? Of these topics, it appears, we must remain silent.
I rank the Books as a masterpiece of philosophical execution. They are magnificently inventive in their models. But I am not convinced that they are so groundbreaking. In switching his focus from the irrefutability of the understood to its implementation, it seems to me Wittgenstein presents a different perspective on the philosophical landscape of the Tractatus than an actually new landscape.
Also, Wittgenstein essentially argues that meaning is composed of arbitrarily applied signifiers that attain meaning only within the systematic play of context. This sounds, to me, a lot like the ideas expounded in Saussure's Course in General Linguistics, published twenty years prior to the writing of these studies. However, in providing a clear and level-headed response to the question, “If language is the source of all knowledge, can thought still conceivably precede expression?” in the form of “conceivably, but not necessarily,” Wittgenstein provides a model of how to approach the subject that makes unnecessary the theoretical bickering over how to follow the implications of Saussure's work that characterized much of the “structuralist vs. post-structuralist” controversies.