In the experience of everyday life, and in almost forty-five years of psychoanalytic practice, a great number of observations and insights into the emotional differences of men and women have been gathered. Not all of them deserved to be followed up. Many of the things observed were lost because they were not written down. Sometimes, however, in pauses between books, I would take the folders from the drawer of my desk that contained this material gathered through the years; many sheets were thrown out, and many others describing new experiences were added. Some of the differences between the sexes that were less visible and had been less clearly perceived demanded to be analytically explored. Some others were briefly discussed because they had escaped the attention of psychologists.