“If, then, it became so difficult, so nearly impossible, in most cases, to determine what is, and what is not, vice; and especially if it be so difficult, in nearly all cases, to determine where virtue ends, and vice begins; and if these questions, which no one can really and truly determine for anybody but himself, are not to be left free and open for experiment by all, each person is deprived of the highest of all his rights as a human being, to wit: his right to inquire, investigate, reason, try experiments, judge, and ascertain for himself, what is, to him, virtue, and what is, to him, vice; in other words: what, on the whole, conduces to his happiness, and what, on the whole, tends to his unhappiness. If this great right is not to be left free and open to all, then each man’s whole right, as a reasoning human being, to ‘liberty and the pursuit of happiness,’ is denied him.

We all come into the world in ignorance of ourselves, and of everything around us. By a fundamental law of our natures we are all constantly impelled by the desire of happiness, and the fear of pain… No one of us, therefore, can learn this indispensable lesson of happiness and unhappiness, of virtue and vice, for another. Each must learn it for himself.”