According to traditional French historiography, French scientific psychology was born when it differentiated itself from philosophy. This split between the two disciplines is attributed to Taine and Ribot, who, consequently, are considered to be the “founding fathers” of French psychology. In this paper we shall examine the case of Pierre Janet, who, at the turn of the century, was recognized worldwide as the most important French psychologist. It is generally said that he was the follower of Ribot and of Charcot. However, he was also Paul Janet's nephew. Paul Janet was a very well known and influential philosopher of the so-called French “spiritualistic” school, for which psychology was central to philosophy. In 1889, Pierre Janet published his doctoral dissertation, L'Automatisme psychologique, which was immediately considered to be a classic in psychology. We shall argue that this book is as much indebted to the old spiritualistic psychology, which claimed the substantial unity of the self, as to the new psychology at the time, which questioned it. With Pierre Janet, the split between psychology and philosophy in France was reconsidered. It would be more accurate to speak in terms of a compromise between philosophy and the “new” physiological and pathological psychology. © 2000 John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]