=Continence in Man.=--Abstinence or sexual continence is by no means impracticable for a normal young man of average constitution, assiduous in intellectual and physical work, abstaining from all artificial excitations, especially from all narcotics and alcohol in particular, for these substances paralyze the judgment and will. When sexual maturity is complete, that is after about twenty years, continence is usually facilitated by nocturnal emissions accompanied by corresponding dreams. The health does not suffer from these in any way. However, in the long run this state cannot be considered as normal, especially when there is no hope of it coming to an end in a reasonable time. What is much more abnormal are the numerous artificial sexual excitations that civilization brings with it. =Sexual Power.=--The individual variations in the sexual instinct are enormous, and may be said to vary from zero to an intense and perpetual excitation called _Satyriasis_. By sexual power is understood the faculty of accomplishing coitus. This power in the first place requires strong and complete erections, as well as the faculty of following them by frequent seminal ejaculations, without being precipitate. Impotence or incapacity for coitus belongs to pathology and consists usually in the absence or defectiveness of erections. Sexual power and appetite generally go together, but not always, for it is possible to be powerful with feeble sexual appetite, and intense appetite sometimes goes with impotence; the latter condition, it is true, is pathological. Sexual power also varies so much in individuals that it is hardly possible to fix a limit between the normal and the pathological. The sexual power and appetite in man are strongest on the average between 20 and 40 years, especially between 25 and 35. But, while young men of 18 to 20 years or more may be still tranquil, without having had seminal ejaculations, one often finds, among races who mature earlier, boys of 12 or 16 who are fully developed both in sexual power and appetite. In our Aryan races, however, when this occurs before the age of 14, it is a case of pathological precocity. The late appearance of sexual power and appetite is rather a sign of strength and health. After the age of 40, the sexual power slowly diminishes, and after the seventieth year, or even before this, becomes extinct. Exceptionally one finds old men of 80 who are still capable. Normally the sexual appetite diminishes with age; often, however, especially when it is artificially excited, it lasts longer than sexual power.