Complex sentence: It is based on the ideas elaborated by John Locke in his "Second Treatise of Government"--that self-ownership allows a person the freedom to mix his or her labor with natural resources, thus converting common property into private property.
Split into simpler sentences: It is based on the ideas elaborated by John Locke in his Second Treatise of Government. Locke's ideas of self-ownership allow a person the freedom to mix his or her labor with natural resources, originally common property, thus making it their private property.