This book is one of the sources of the reversal in the Anglo-American conception of what Wittgenstein's Tractatus is all about. When it was published in 1973, it makes the point that the Continental view that the last few pages of summary really was just that; Wittgenstein was concerned with showing what propositional logic could not say, and what it could not say is all the important stuff (like meaning, ethics, moving on). In contrast, the analytic philosophers of England and America saw Wittgenstein's conclusion as a strange aside, by a famously strange personality, in an otherwise brilliant extension of Russell and Frege's exposition of the logic of language. Janik and Toulmin's very interesting cultural history of Vienna around the turn of the twentieth century wants to show that Wittgenstein, instead of being that strange genius, was just being Viennese.
When I was assigned Philosophical Investigations in a class given in the early 70's, it was assumed that this work was a complete break with the logical rigor of his early years, and that this strange genius had moved on to nobler concerns. Janik and Toulmin argue that Wittegenstein's concerns are quite consistent throughout his life, in contrast to earlier academics who viewed his early work as radically divorced from his later thought, each side highlighting the Wittgenstein that conformed to their own analytic or Continental tunnel vision.
If one accepts the view that Wittgenstein's concerns were consistent throughout his life, it is nevertheless impossible to discount the very different relationship language has to the world in later and early Wittgenstein. In the Tractatus, the logic of language, when used for science and practical, everyday use, does conform to the world, making it a truthful relationship. This truthful relationship is just what language cannot catch with value systems. In later Wittgenstein, any contact with the world has been eclipsed by relations with human behavior. Language games, dictating how we behave with either conscious or unconscious rule following, is an enclosed system, concerned with how we get the cultural needs accomplished, and always embedded in other cultural matrices. Though Janik and Toulmin have no interest in making this connection, I would place late Wittgenstein in that great movement from substantive ways of thinking to relational ones, epitomized most directly by Saussurean linguistics. From there the movement flows through Foucault's epistemes to Kuhn's paradigms and many other European theorists who thought of themselves as structuralists and then post-structuralists. For all these people, as for late Wittgenstein, linguistic entities are not anchored to the world, but only to each other, in fact creating substances by their placement in a system. Wittgenstein was particularly behavior oriented; he always counseled to look and see what rules of behavior (language games) were being demonstrated by the action, linguistic or otherwise, under
inspection.
So, what Wittgenstein appears to have been consistent in is his lifelong and vehement demarcation of practical, scientific statement from spiritual, ethical concerns. In the Tractatus, this was justified, in fact proven, from his point of view. However, any language game is successful if it accomplishes a need in a cultural matrix. Thus ethical and religious language games are based on exactly the same footing as scientific and practical systems. How, then, can Wittgenstein continue to assume this huge chasm? For Janik and Toulmin, it's with the extreme cultural context of his early years in Vienna, and, really, for psychological reasons. Perhaps we have returned to the strange genius again, no matter how reluctantly.