Propertarianism
Producer's Right
Territory is a fact among animals. An individual or group establishes control of a certain extent of land.
Property, that a man's body and the work of his hands belong to him, is a widespread intuition. This human intuition of property seems to be a refinement of that zoological fact.
Robert Nozick, in Chapter 8 of Anarchy, State, and Utopia, notes how Marxism and similar theories, claiming to explain property as a kind of froth arising from a substance consisting of "relations of production", in fact presuppose the notion of property in their description of the substance. This illustrates how deeply embedded the principle is in our consciousness.
The property intuition is that producers own their produce. Even those who reject the Psalmist's premise usually endorse his logic:
It is he that has made us, and we are his.
Psalm 100
This principle is called Producer's Right.
Producer's Right can be expressed in the acronym WIMIO ("What I make I own") or more technically as "Kataskeuazalism" from Greek kataskeuazo ("make" or "build") or "Opifectodominalism" from Latin opifex dominus ("the maker is the master").
Many find excuses to set Producer's Right aside, but few deny it outright. In general, only societies sunk in savagery seem to lack it altogether. To deny that a producer has any special rights, to repress the territorial instinct, is to regard man as less than beast. Those who deny Producer's Right in words seldom deny it in practice, especially when their own produce is concerned.
Land
Producer's right entitles homesteaders to the value they have added, but not to own the land as such. Land is never wholly owned.
For more details on landholding, see Landholding...
Inventions
There is no "Intellectual Property". An inventions is a thought not a product, and my thinking it first gives me no right to stop you thinking it afterwards.