Ludwig Wittgenstein (1889–1951) had two distinct philosophical periods. First, was his ambitious development of logical atomism that was influenced by his teacher Bertrand Russell (1872–1970), resulting in his writing Tractatus Logico-Philosophicus (1921). Second was Wittgenstein’s original, “ordinary language” theory of philosophy. This was an original insight about ordinary language. Wittgenstein was unquestionably a genius.