Wittgenstein's Tractatus Logico-Philosophicus is a book of philosophy written in short, seemingly oracular, numbered remarks. Its conclusion suggests that those who understand its author will regard as nonsense the elucidatory propositions that constitute the majority of the text. Wittgenstein seems to say that if we see the point of his book, we must throw it away. I still have my copy, purchased many years ago when I was an undergraduate student. Perhaps I have not really grasped its message, or maybe it is a message to which one must constantly return.
The sheer oddness of the Tractatus may explain in part its reception. Completed when Wittgenstein was in an Italian prison camp in Cassino towards the end of the First World War, the book may seem to address well-known philosophical topics. From the very beginning, interpreters read this work as a text espousing doctrines. They took its conclusion to be inessential and proposed to ignore it or treat it as a mere side effect of the ineffability of the views expressed within the work. These doctrines were said to concern the nature of the world (which was the totality of facts); the fundamental constituents of reality, conceived as immutable, indivisible objects; language (whose function is to picture the world by sharing its logical form); and logic.
Wittgenstein opposed all these attempts to normalise his book. Thus, despite prolonged difficulties with finding a publisher, he resisted any changes in the text and lamented that even though the book was crystal clear, no one understood it. He apparently stunned the Vienna Circle positivists, who had invited him to discuss his work, by reading poems of the Bengali poet Rabindranath Tagore while sitting with his back to them. The positivists had understood him to say that all religion, ethics and metaphysics is vacuous nonsense; he riposted that it is nonsense all right - and yet it is of the utmost importance.
Philosophical interest in the Tractatus ebbed away during the middle of the 20th century, under the influence of Wittgenstein's later work, which was taken to be an almost complete rejection of the so-called doctrines of his earlier book. It is only since the mid-1980s that it has become again the focus of renewed intense discussion, concentrating on the nature of philosophy itself. Some new critics read the Tractatus as an aid to reveal the mistakes of the view that there are doctrines in philosophy. Others, instead, merely protest that "the Tractatus is not all rubbish".
Whether or not it was intended to convey information of a philosophical kind, the Tractatus is also a work of art. It is thus no surprise that it has been a source of inspiration for artists ranging from Steve Reich, who has set some of Wittgenstein's work to music, to the conceptual artist Joseph Kosuth, and to Derek Jarman, whose 1993 film, Wittgenstein, beautifully conveys the fascinating character of both this work and its author.