" I think it will be but a very modest computation to say, that of the products of the earth useful to the life of man, nine-tenths are the effects of labour: nay, if we will rightly estimate things as they come to our use, and cast up the several expenses about them, what in them is purely owing to nature, and what to labour, we shall find, that in most of them ninety-nine hundredths are wholly to be put on the account of labour. "

― John Locke , Two Treatises of Government and A Letter Concerning Toleration