Wittgenstein is famous for revolutionizing philosophy not once but twice. He claimed to have solved all the problems of philosophy in his Tractatus Logico-Philosophicus, only to return to philosophy ten years later, repudiate many of the central claims of the Tractatus,and reinvent philosophy a second time with thePhilosophical Investigations.
Among the central differences between the early Wittgenstein of the Tractatus and the later Wittgenstein of the Philosophical Investigations and his various notebook writings is a shift in emphasis regarding the importance of logic.
In the Tractatus, logic is given central importance as determining the structure of language and reality, but it receives scarcely a mention in the Investigations.
Wittgenstein’s later philosophy abandons the rigidly structured world of the Tractatus in favor of a less pristine and more modest conception of a complex world that resists any simple articulation.
While the differences between the early and later philosophies of Wittgenstein go deep, significant similarities remain. The four themes that follow trace some of the most important points on which Wittgenstein’s position does not change radically throughout his career.