[A] feeling of liking or aversion to an action, confined to an individual, would have no chance of being accepted as a reason. The appeal is always to something which is assumed to belong to all mankind. But it is not of much consequence whether the feeling which is set up as its own standard is the feling of an individual human being, or of a multitude. A feeling is not proved to be right, and exempted from the necessity of justifying itself, because the writer or speaker is not only conscious of it in himself, but expects to find in other people, because instead of saying “I,” he says “you and I.”

John Stuart Mill, ‘Whewell on Moral Philosophy’, in The Collected Works of John Stuart Mill, Toronto, 1988, vol. 10, pp. 178-179