The virtue of Chastity is subservient to the utility of rearing the young, which requires the combination of both parents; and that combination reposes on marital fidelity. Without such a utility, the virtue would never have been thought of. The reason why chastity is extended to cases where child-bearing does not enter, is that general rules are often carried beyond their original occasion, especially in matters of taste and sentiment.
The prohibition of marriage between near relations, and the turpitude of incest, have in view the preserving of purity of manners among persons much together.
The laws of good manners are a kind of lesser morality, for the better securing of our pleasures in society.
Even robbers and pirates must have their laws. Immoral gallantries, where authorized, are governed by a set of rules. Societies for play have laws for the conduct of the game. War has its laws as well as peace. The fights of boxers, wrestlers, and such like, are subject to rules. For all such cases, the common interest and utility begets a standard of right and wrong in those concerned.
Section V. proceeds to argue WHY UTILITY PLEASES. However powerful education may be in forming men's sentiments, there must, in such a matter as morality, be some deep natural distinction to work upon. Now, there are only two natural sentiments that Utility can appeal to: (1) Self-Interest, and (2) Generosity, or the interests of others.
The deduction of morals from Self-Love is obvious, and no doubt explains much. An appeal to experience, however, shows its defects. We praise virtuous actions in remote ages and countries, where our own interests are out of the question. Even when we have a private interest in some virtuous action, our praise avoids that part of it, and prefers to fasten on what we are not interested in. When we hear of the details of a generous action, we are moved by it, before we know when or where it took place. Nor will the force of imagination account for the feeling in those cases; if we have an eye solely to our own real interest, it is not conceivable how we can be moved by a mere imaginary interest.
But another view may be taken. Some have maintained that the public interest is our own interest, and is therefore promoted by our self-love. The reply is that the two are often opposed to each other, and still we approve of the preference of the public interest. We are, therefore, driven to adopt a more public affection, and to admit that the interests of society, on their own, account, are not indifferent to us.
Have we any difficulty to comprehend the force of humanity or benevolence? Or to conceive that the very aspect of happiness, joy, prosperity, gives pleasure; while pain, suffering, sorrow, communicate uneasiness? Here we have an unmistakeable, powerful, universal sentiment of human nature to build upon.
The author gives an expanded illustration of the workings of Benevolence or Sympathy, which well deserves to be read for its merits of execution. We must here content ourselves with stating that it is on this principle of disinterested action, belonging to our nature, that he founds the chief part of our sentiment of Moral Approbation.