Buddy diving just before and after the Second World War. After the invention of the "aqualung" by Cousteau and Gagnan, the first commercially underwater breathing apparatus became available for sale for sporting purposes in the late 1940s. As the new sport of scuba diving rapidly expanded through the 1950s, several sporting organisations—notably the YMCA—began programmes to train swimming enthusiasts in this new aquatic pastime, and began to codify what they believed were proper practises for this expanding sport. The YMCA considered the buddy system a useful corollary to the "never swim alone" rule of their swimming and lifesaving programmes. Cousteau himself independently
20th-century French philosophy linguistics in the 20th century. He is widely considered the 'father' of 20th-century linguistics. This current was further explored by Claude-Levi Strauss in ethnology. His work influenced important figures like Jacques Derrida and Jacques Lacan significantly. From 1963, a magazine was run in Paris, called Tel Quel, which also dabbled excessively in structuralist analysis of texts. Important figures in this endeavour were Phillip Sollers, the magazine's editor, Julia Kristeva and Roland Barthes. Jacques Lacan (1901–1981) was specifically interested in the philosophy of psychoanalysis. He could be said to be relevant to the more modern foundations of discursive psychology. Post-structuralism is,