To "Tractatus Logico-Philosophicus" (Λογικο-Φιλοσοφική Πραγματεία) is the only philosophical work published by Ludwig Wittgenstein during his lifetime. Today it is considered one of the most important philosophical texts of the 20th century, inaugurating a new direction in philosophy that concerned the analysis of language.

The "Tractatus Logico-Philosophicus" was the "Bible" of the Vienna Circle and had a significant influence on the Cambridge analysis school in the 1920s and 1930s. It inspired the movement of logical positivism, which in turn became the most influential philosophical movement of the 20th century. After its completion, Wittgenstein believed that he had solved all the traditional problems of philosophy, which he abandoned for about a decade. This work is characterized as one of the most enigmatic philosophical texts of all time, inspiring extensive literature, but without a general agreement on its interpretation.

For what one cannot speak about,
one must remain silent.
L. Wittgenstein