The ethics of interest are nothing else than the ethics of perfected pleasure, substituting happiness for pleasure, the useful for the agreeable, prudence for passion. It admits, like the human race, the words good and evil, virtue and vice, merit and demerit, punishment and reward, but it explains them in its own way. The good is that which in the eyes of reason is conformed to our true interest; evil is that which is contrary to our true interest. Virtue is that wisdom which knows how to resist the enticement of passions, discerns what is truly useful, and surely proceeds to happiness. Vice is that aberration of mind and character that sacrifices happiness to pleasures without duration or full of dangers. Merit and demerit, punishment and reward, are the consequences of virtue and vice:--for not knowing how to seek happiness by the road of wisdom, we are punished by not attaining it. The ethics of interest do not pretend to destroy any of the duties consecrated by public opinion; it establishes that all are conformed to our personal interest, and it is thereby that they are duties. To do good to men is the surest means of making them do good to us; and it is also the means of acquiring their esteem, their good will, and their sympathy,--always agreeable, and often useful. Disinterestedness itself has its explanation. Doubtless there is no disinterestedness in the vulgar sense of the word, that is to say, a real sacrifice of self, which is absurd, but there is the sacrifice of present interest to future interest, of gross and sensual passion to a nobler and more delicate pleasure. Sometimes one renders to himself a bad account of the pleasure that he pursues, and in fault of seeing clearly into his own heart, invents that chimera of disinterestedness of which human nature is incapable, which it cannot even comprehend. It will be conceded that this explanation of the ethics of interest is not overcharged, that it is faithful. We go further,--we acknowledge that these ethics are an extreme, but, up to a certain point, a legitimate reaction against the excessive rigor of stoical ethics, especially ascetic ethics that smother sensibility instead of regulating it, and, in order to save the soul from passions, demands of it a sacrifice of all the passions of nature that resembles a suicide.