Let it be said in passing that, however much my metaphysics of love may displease those in love, the fundamental truth revealed by me would enable them more effectually than anything else to overcome their passion, if considerations of reason in general could be of any avail. The words of the comic poet of ancient times remain good: _Quae res in se neque consilium, neque modum habet ullum, eam consilio regere non potes_. People who marry for love do so in the interest of the species and not of the individuals. It is true that the persons concerned imagine they are promoting their own happiness; but their real aim, which is one they are unconscious of, is to bring forth an individual which can be begotten by them alone. This purpose having brought them together, they ought henceforth to try and make the best of things. But it very frequently happens that two people who have been brought together by this instinctive illusion, which is the essence of passionate love, are in every other respect temperamentally different. This becomes apparent when the illusion wears off, as it necessarily must. Accordingly, people who marry for love are generally unhappy, for such people look after the welfare of the future generation at the expense of the present. _Quien se casa por amores, ha de vivir con dolores_ (He who marries for love must live in grief), says the Spanish proverb. Marriages _de convenance_, which are generally arranged by the parents, will turn out the reverse. The considerations in this case which control them, whatever their nature may be, are at any rate real and unable to vanish of themselves. A marriage of this kind attends to the welfare of the present generation to the detriment of the future, it is true; and yet this remains problematical. A man who marries for money, and not for love, lives more in the interest of the individual than in that of the species; a condition exactly opposed to truth; therefore it is unnatural and rouses a certain feeling of contempt. A girl who against the wish of her parents refuses to marry a rich man, still young, and ignores all considerations of _convenance_, in order to choose another instinctively to her liking, sacrifices her individual welfare to the species. But it is for this very reason that she meets with a certain approval, for she has given preference to what was more important and acted in the spirit of nature (of the species) more exactly; while the parents advised only in the spirit of individual egoism.