I perceive that you don’t approve of my joking about such serious matters. It is not altogether a joke, however. Seriously, it is not so easy to define what the term sexual includes. Everything connected with the difference between the two sexes is perhaps the only way of hitting the mark; but you will find that too general and indefinite. If you take the sexual act itself as the central point, you will perhaps declare sexual to mean everything which is concerned with obtaining pleasurable gratification from the body (and particularly the sexual organs) of the opposite sex; in the narrowest sense, everything which is directed to the union of the genital organs and the performance of the sexual act. In doing so, however, you come very near to reckoning the sexual and the improper as identical, and childbirth would really have nothing to do with sex. If then you make the function of reproduction the kernel of sexuality you run the risk of excluding from it a whole host of things like masturbation, or even kissing, which are not directed towards reproduction, but which are nevertheless undoubtedly sexual. However, we have already found that attempts at definition always lead to difficulties; let us give up trying to do any better in this particular case. We may suspect that in the development of the concept “sexual” something has happened which has resulted in what H. Silberer has aptly called a ‘covering error.’ On the whole, indeed, we know pretty well what is meant by sexual.