He that is nourished by the acorns he picked up under an oak, or the apples he gathered from the trees in the wood, has certainly appropriated them to himself. Nobody can deny but the nourishment is his. I ask, then, when did they begin to be his? when he digested? or when he eat? or when he boiled? or when he brought them home? or when he picked them up?

— John Locke, An Essay Concerning the True Original, Extent and End of Civil Government, 1689