act. This similarity leads him to assume the sexual quality in the act of suckling. This conclusion is only admissible if it can be proved that the tension of the need, and its gratification by a release, is a sexual process. That the act of suckling has this emotional mechanism proves, however, just the contrary. Therefore we can only say this emotional mechanism is found both in nutrition and in the sexual function. If Freud by analogy deduces the sexual quality of sucking from this emotional mechanism, then his biological empiricism would also justify the terminology qualifying the sexual act as a function of nutrition. This is unjustifiably exceeding the bounds in either case. It is evident that the act of sucking cannot be qualified as sexual.
We are aware, however, of functions in the suckling stage which have apparently nothing to do with the function of nutrition, such as sucking the finger, and its many variations. This is perhaps the place to discuss whether these things belong to the sexual sphere. These acts do not subserve nutrition, but produce pleasure. Of that there is no doubt, but nevertheless it is disputable whether this pleasure which comes by sucking should be called by analogy a sexual satisfaction. It might be called equally pleasure by nutrition. This latter qualification has even the further justification that the form and kind of pleasure belong entirely to the function of nutrition. The hand which is used for sucking finds in this way preparation for future use in feeding one's self. Under these circumstances nobody will be inclined by a petitio principii to characterize the first manifestation of human life as sexual. The statement which we make that the act of sucking is attended by a feeling of satisfaction leaves us in doubt whether the sucking does contain anything else but the character of nutrition. We notice that the so-called bad habits shown by a child as it grows up are closely linked with early infantile sucking, such for instance as putting the finger in the mouth, biting the nails, picking the nose, ears, etc. We see, too, how closely these habits are connected with later masturbation. By analogy, the conclusion that these infantile habits are the first step to onanism, or to actions similar to onanism, and are therefore of a well-marked sexual character cannot be denied: it is perfectly justified. I have seen many cases in which a correlation existed between these childish habits and later masturbation. If
