Tractatus Logico-Philosophicus
The Tractatus Logico-Philosophicus (widely abbreviated and cited as TLP) is the only book-length philosophical work by the Austrian philosopher Ludwig Wittgenstein that was published during his lifetime. The project had a broad goal: to identify the relationship between language and reality, and to define the limits of science.
Source: Wikipedia — Tractatus Logico-Philosophicus (CC BY-SA 4.0)