Ludwig Wittgenstein was an influential 20th-century philosopher who made significant contributions to logic, the philosophy of language, and the philosophy of mind. He is best known for two major works: the "Tractatus Logico-Philosophicus," which attempted to solve all philosophical problems through logical analysis of language, and "Philosophical Investigations," which explored the complexities of language use in everyday life. Wittgenstein's ideas had a profound impact on analytic philosophy and continue to be widely studied and debated today.