The following proposition seems to me in a high degree probable—namely, that any animal whatever, endowed with well-marked social instincts, the parental and filial affections being here included, would inevitably acquire a moral sense or conscience, as soon as its intellectual powers had become as well, or nearly as well developed, as in man. For, firstly, the social instincts lead an animal to take pleasure in the society of its fellows, to feel a certain amount of sympathy with them, and to perform various services for them.

What we now call "morality" was evolved – as nearly all social and physical human attributes were – to aid us in survival and, ultimately, reproduction. This morality requires only that we be guided by our developed conscience (or "moral sense") – and not a God or gods.

The practice of that which is ethically best—what we call goodness or virtue—involves a course of conduct which, in all respects, is opposed to that which leads to success in the cosmic struggle for existence. In place of ruthless self-assertion it demands self-restraint; in place of thrusting aside, or treading down, all competitors, it requires that the individual shall not merely respect, but shall help his fellows... It repudiates the gladiatorial theory of existence... Laws and moral precepts are directed to the end of curbing the cosmic process.