Tractatus Logico-Philosophicus

Tractatus Logico-Philosophicus is the only work published by Ludwig Wittgenstein in his lifetime.

English online versions:

• http://www.kfs.org/~jonathan/witt/tlph.html
• http://users.compaqnet.be/cn111132/wittgenstein/tractatus_logico_philosophicus.htm
• http://guava.phil.lehigh.edu/tlp/