 … before the desire of having more than one needed had altered the intrinsic value of things, which depends only on their usefulness to the life of man; or had agreed, that a little piece of yellow metal, which would keep without wasting or decay, should be worth a great piece of flesh, or a whole heap of corn; though men had a right to appropriate by their labor, each one of himself, as much of the things of nature, as he could use; yet this could not be much, nor to the prejudice of others, where the same plenty was left to those who would use the same industry. (Treatises II.5.37)