In the question of the prevention of syphilis, the moral problem is still more easy to settle. Whilst in the case of vivisection a real suffering may be inflicted upon animals, in preventive measures against syphilis, the evil is more or less intricate and very problematic. The certainty of safety from this disease might render extra-conjugal relations more frequent, but if we compare the evil which might come from that with the immense benefit gained in preventing so many innocent persons from becoming diseased, it is easy to see to which side the scale dips. The indignation of those who protest against the discovery of preventive measures can never either arrest the zeal of the investigators or hinder the use of the measures. This example again shows that reasoning is necessary in the solution of most moral questions. However, the problems which arise in actual life are often very much more complicated than the two cases I have taken as an introduction. It is easy to prove the high utility of the work of vivisectors and of those who are seeking means of preventing syphilis, whilst their adversaries have nothing to invoke but their feelings. The situation is quite different in many questions which border on morality. The sexual life abounds in extremely difficult problems, in which it is almost impossible to determine what is right. Let me recall the vagaries in the life of Goethe, whose great genius was so often in conflict with the morality of his time. Was he wrong in giving up Frederique and Lili from the fear that a permanent bond would damage his poetic productivity? Then there is the moral question of the marriage of men affected with syphilis, or other diseases which might influence the offspring. The problems of the continence of young people before marriage, of prostitution and of means of preventing conception are without doubt questions of great importance, the solution of which is extremely difficult from the point of view of morality. Differences of opinion are revealed in nearly everything relating to punishment. The question of the death penalty is much in dispute and requires numerous investigations of different kinds. Statistics have been collected to give information as to the utility or inutility of the death penalty. According to some results, capital punishment does not diminish the number of crimes, whilst according to others it has a real preventive effect. Punishments less violent than death, and particularly the punishments of children, are equally troublesome, and schoolmasters have difficulty in finding a solution. The utilitarian theory of morality often finds it impossible to prove the advantage of the conduct it prescribes, and this the more because in many cases we do not exactly know who is to profit by it. Is the utility of any particular act to be considered so far as it affects relatives, members of the same religion, of the same country, or of the same race, or all humanity?