John Locke was a 17th Century English philosopher. Today, his definition of self-ownership is commonly referred to as the best definition. His definition of self-ownership meant, as might be obvious, owning yourself. This is because only you have the moral claim over you own body. Only you can control yourself and do stuff like donating an organ. Out of his idea of self ownership, comes the idea of private property. John Locke said that if a person mixed their labor with something, then it became theirs. In English, this means that if somebody puts work and effort into something, then it rightfully becomes their private property.