Ludwig Wittgenstein (1889–1951) is regarded as one of the most influential and eminent philosophers of the twentieth century. In both his early and later work, he is a key figure in the development of analytical philosophy: he wants us to see that natural language use is pivotal to understanding the nature of the mind. However, his later work, specifically with regard to the Philosophical Investigations (1953) [henceforth referred to as the Investigations], where concepts are a participating part of the context, makes him a key figure in contemporary cognitive psychology. While Wittgenstein’s interest in psychology began between 1934-1936 when he lectured on private experience and sense data, his contributions to the field of psychology continued up until his death in 1951. Unknown to Wittgenstein at the time, his remarks on philosophical psychology would have an enormous influence on both the psychology and philosophy disciplines.