THE adaptation of the whole mechanism of erection is so excellent, that we should now like to say a little about it from a theoretical standpoint. In the period of enlightenment which followed on the theological middle ages people turned their attention once more to the study of nature, and they were especially delighted with the adaptation of various phenomena. But to the leaders of this movement, such as Bernardin de St. Pierre and Sussmilch, it was soon apparent that this method places us at the mercy of a boundless imagination. Darwin was the first to formulate a new principlethat adaptation ensured the survival of the fittest. But even this does not by any means remove the danger of subjectivity.
Meanwhile in the field of mechanics and physics another method has been shown by experience to be most successful, namely the investigation of the chain of causality. But at first it was not possible for them to apply this method to living Nature with its endless complications, because they sought adaptation in everything. It was only later that men began to investigate free from prejudice, and to recognise imperfections in Nature itself. So we no longer regard adapts. tion as an invariable thing, but only secondary and auxiliary, because as a working hypothesis it can often point out the way by which we can trace the causal connection.
Yet, whether we speak of adaptation or non-adaptation, we must never forget that these are only phrasesand so must only be taken as relative.
Although not introduced pedantically every time, this prudent mental reservation must always be thought of when in this work I speak of adaptation or non-adaptation; phrases which would otherwise be rash and presumptuous. It is not possible for us men to regard all things in their mutual relationships, because in Nature two sort of phenomena occur, which are diametrically opposed to each otherconstruction and destruction, progression and retrogression, which, however, are interdependent.
If we term the connection of natural phenomena “adaptation,” that is really a figure of speech, as though we were speaking of human actions consequent on human considerations; and it would seem as though we had dared theologically to take the stand that we had some insight into the purposes which have ruled in creation since the beginning of all things. But in the study of Nature it is not permissible to speak literally of Nature’s purpose. In Nature we can only recognise cause and effect, or more correctly speaking, really only a constant occurrence of phenomena side by side and one after the other, from which we may guess with more or less success, the probabilities of the future series of events.
Only in our brain as the highest power of cell-life, our imagination often conjures up pictures of future acts, which then predispose us to the committal of these acts. Our brain can also keep a certain future purpose in view; and we term our acts, adapted, especially when they are adapted to the fulfilment of this premeditated purpose, and still more commonly if they agree with what we have in view.
In Nature also we observe phenomena, which surprise us, because if we men had so arranged things ourselves according to our own plans, they could not have been better or more expedient.
This impression is so irresistible that anthropomorphically also we speak of adaptation. And this mode of expression is really so brief and practical that I have already used it frequently; only it must be rightly understood.
In Nature we call everything adapted that is well organised, and almost everything in Nature is thoroughly well organised. In living Nature especially, the conditions of existence are so complicated that everything that is not fairly well adapted is not at all capable of existence; it ceases to live, or it reproduces its kind less extensively (Darwin) than better organised individuals.
And the evolution of organs through exercise (Lamarck) implies a process of adaptation. Thus cell-life really develops as a beautiful whole, with a wealth of adaptations. To trace these out will always be one of the most delightful and pleasurable tasks of Nature-study. And so we continue to employ this picturesque phrase, though really we can only find a chain of causes and effects.
Such modes of expression only become dangerous if we allow ourselves to be led by them into too great a generalisation of the idea of adaptation if, for instance, we wish to establish a systematic view of life on this conception of adaptation, for only too often that runs counter to experience.
I have gone so exhaustively into the subject of the adaptation of the mechanism of erection, only because I must refer in so many other places to shortcomings, errors and non-adaptations of the sexual organisation.
If then we finally enquire why we consider the mechanism of erection so well adapted to its aim, the answer must be that we have in mind the guarantee of the desired result, for through it we are so absolutely driven to coitus, and cannot effect coitus without it, whereby reproduction of the species is the better guaranteed. For fertilisation is the principal factor in the preservation of the species.
But the answer may be extended to all useful results, such as: increase in blood pressure, intensification of our vital energy and the joy of living! For all these things are also factors which afford effective help in the struggle for existence. Above all, however, one should be careful not to imagine that the one excludes, or ought to exclude the other.
It is, however, literally correct to speak of the purpose of our sexual life, as far as we mean thereby our human deeds, which should always he well thought out. And here also it is true that we scarcely ever have only one purpose in mind; the action only ripens when several motives work together. Thus we are led to copulation through our sexual impulse, i.e., through the above described antagonism; or by the wish to render each other mutually happy, or in the hope of producing children. And all these motives do not by any means exclude each other; and ultimately we use Nature to attain our own ends.
We do not desire to limit ourselves in this work to the question of the reproduction of the species, as though that were the only purpose of the sexual life. This has already been done too often. On the contrary we now want to study first of all the primary effects of sexual excitement: lust and love, both motives that have been scientifically far too neglected up to the present, and which are yet of vital importance for our life’s happiness and conduct. By this restriction the book may lose in completeness, but even within these bounds there is abundant material.
If we enquire the purpose of our sexual life even with this reservation, we scarcely dare give an answer, on account of the vastness of the subject. One might just as well enquire after the purpose of life itself. Life is a search for self-expression, and sexuality is only a more intense expression of life. We will not worry further with the question: what is the purpose of life? As in all problems, the sexual life must have a purpose of its own, so that it may become as pure, as strong and as beautiful as possible.