Happiness, like pleasure, is relative to him who experiences it; it is essentially personal. Ourselves, and ourselves alone we love, in loving pleasure and happiness.

Interest is that which prompts us to seek in every thing our pleasure and our happiness.

If happiness is the sole end of life, interest is the sole motive of all our actions.

Man is only sensible to his interest, but he understands it well or ill. Much art is necessary in order to be happy. We are not ready to give ourselves up to all the pleasures that are offered on the highway of life, without examining whether these pleasures do not conceal many a pain. Present pleasure is not every thing,—it is necessary to take thought for the future; it is necessary to know how to renounce joys that may bring regret, and sacrifice pleasure to happiness, that is to say, to pleasure still, but pleasure more enduring and less intoxicating. The pleasures of the body are not the only ones,—there are other pleasures, those of mind, even those of opinion: the sage tempers them by each other.

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.

Man was not made to be a sublime slave, like Epictetus, employed in supporting bad fortune well without trying to surmount it, nor, like the author of the Imitation, the angelic inhabitant of a cloister, calling for death as a fortunate deliverance, and anticipating it, as far as in him lies, by continual penitence and in mute adoration. The love of pleasure, even the passions, have a place among the needs of humanity. Suppress the passions, and it is true there is no more excess; neither is there any mainspring of action,—without winds the vessel no longer proceeds, and soon sinks in the deep. Suppose a being that lacks love of self, the instinct of preservation, the horror of suffering, especially the horror of death, who has neither the love of pleasure nor the love of happiness, in a word, destitute of all personal interest,—such a being will not long resist the innumerable causes of destruction that surround and besiege him; he will not remain a day. Never can a single family, nor the least society be formed or maintained. He who has made man has not confided the care of his work to virtue alone, to devotedness and sublime charity,—he has willed that the duration and development of the race and human society should be placed upon simpler and surer foundations; and this is the reason why he has given to man the love of self, the instinct of preservation, the taste of pleasure and happiness, the passions that animate life, hope and fear, love, ambition, personal interest, in fine, a powerful, permanent, universal motive that urges us on to continually ameliorate our condition upon the earth.

So we do not contest with the ethics of interest the reality of their principle,—we are convinced that this principle exists, that it has a right to be. The only question that we raise is the following:—The principle of interest is true in itself, but are there not other principles quite as true, quite as real? Man seeks pleasure and happiness, but are there not in him other needs, other sentiments as powerful, as vital? The first and universal principle of human life is the need of the individual to preserve himself; but would this principle suffice to support human life and society entire and as we behold it?

Just as the existence of the body does not hinder that of the soul, and reciprocally, so in the ample bosom of humanity and the profound designs of divine Providence, the principles that differ most do not exclude each other.