The “figurae Veneris legitimae” (modes of natural Love) are not altogether without interest for the physician[230], but their study is less necessary for our particular purpose. The modes of “Venus illegitima” (unnatural Love) are what concern us here. The major part of these have unfortunately never been included by writers on the history of Venereal disease within the range of their enquiries. Hence it has come about that while on the one hand they have given quite false interpretations of various morbid affections, they have on the other mistaken for the names of diseases expressions signifying nothing more than forms of the unnatural sensual indulgence alluded to. The historical enquirer into these subjects must indeed tread very slippery ground. Supposing him to rise superior to the possible reproaches of morality, fortified by the words of St. Paul[231], still he can find absolutely nowhere in his investigations any secure stopping-place, he must make up his mind to dispense with all external help and to be thrown utterly on his own resources. Not only do the best and fullest Dictionaries of the Greek and Latin languages leave him almost completely in the lurch, but above and beyond this he has very often to struggle with positive errors both in the Dictionaries and on the part of the professional Philologists in their annotations to the writings of the Ancients. These mistakes he must first of all discover, and afterwards correct. What such an undertaking involves, what powers it demands, will be obvious to anyone who is in any degree conversant with the systematic study of Antiquity. Nevertheless the task should not remain unattempted, if that is, we wish ever to come to a clear understanding of the relations of words and things in this connection; and on this ground the following researches no less than others find a legitimate place here. These we offer as the best that the limitation of our powers allowed,—at the same time gladly acknowledging the no small assistance we have received from the Treatises of Forberg[232] and Meier[232].