This very remarkable relation of sexual variations ranging from the normal to the insane gives material for reflection. It seems to me that the fact to be explained would show that the impulses of the sexual life belong to those which even normally are most poorly controlled by the higher psychic activities. He who is in any way psychically abnormal, be it in social or ethical conditions, is, according to my experience, regularly so in his sexual life. But many are abnormal in their sexual life who in every other respect correspond to the average; they have followed the human cultural development, but sexuality remained as their weak point. As a general result of these discussions we come to see that, under numerous conditions and among a surprising number of individuals, the nature and value of the sexual object steps into the background. There is something else in the sexual impulse which is the essential and constant.[13] 2. DEVIATION IN REFERENCE TO THE SEXUAL AIM The union of the genitals in the characteristic act of copulation is taken as the normal sexual aim. It serves to loosen the sexual tension and temporarily to quench the sexual desire (gratification analogous to satisfaction of hunger). Yet even in the most normal sexual process those additions are distinguishable, the development of which leads to the aberrations described as _perversions_. Thus certain intermediary relations to the sexual object connected with copulation, such as touching and looking, are recognized as preliminary to the sexual aim. These activities are on the one hand themselves connected with pleasure and on the other hand they enhance the excitement which persists until the definite sexual aim is reached. One definite kind of contiguity, consisting of mutual approximation of the mucous membranes of the lips in the form of a kiss, has received among the most civilized nations a sexual value, though the parts of the body concerned do not belong to the sexual apparatus but form the entrance to the digestive tract. This therefore supplies the factors which allow us to bring the perversions into relation with the normal sexual life, and which are available also for their classification. The perversions are either (_a_) anatomical _transgressions_ of the bodily regions destined for sexual union, or (_b_) a _lingering_ at the intermediary relations to the sexual object which should normally be rapidly passed on the way to the definite sexual aim. (_a_) _Anatomical Transgression_