Although it is generally considered that the study of social psychology in the former Czechoslovakia commenced in the 1960s, the author here establishes the importance of the virtually forgotten earlier years of the discipline. The first Czech student of social psychology was a prominent sociologist and member of the Prague sociological school, Otakar Machotka (1899- 1970), whose interest in matters psychological commenced in the 1940s and whose research into the subject continued during his period of exile in America in the 1950s and 1960s. Machotka’s recently discovered post-war manuscript on the subject of unconscious agents in social behaviour, which is published in extenso here, reveals the original and innovative character of the author’s approach; at the same time, it offers an important testimony to the epoch both in terms of the discipline itself and the wider society. The erstwhile unknown manuscript also contains the first stage of Machotka’s struggle for an explanation for quisling behaviour during the Second World War, which he later published in his 1964 book., Zdeněk R. Nešpor., and Obsahuje seznam literatury