Through the process of argumentation, one can demonstrate the existence of natural rights and define them.
An argument automatically acknowledges that peaceful means for the resolution of conflict exists because violence is not involved.
If one engages in violence, it is no longer an argument.
An argument must be able to convince the entirety of the world (in theory at least) that it is correct, therefore a logical argument can not be limited in favor of a subset of individuals.
If I say this group should have these rights while another group should not, the argument fails this universality test.
Secondly, an argument must not be contradictory in nature. For example, I can not argue that reason does not exist because I am implicitly using reason to argue my point.
From this, the origination of rights in a peaceful society can be derived.
If we say that a right is the free action of an individual, where by it would be immoral to stop an individual from engaging in that action, this argument passes the universality, contradiction and violence tests.
If we say that ownership of property originates in first use, were by the first person to combine his labor with that resource owns that resource, we can say that this argument also passes the universality, contradiction and violence tests.
If we say that an individual has self-ownership, that is, he owns himself and is free to do with himself as he pleases, this passes the universality, contradiction and violence tests.
If we say that a person may not damage or forcibly take the property of another, this to passes the universality, contradiction and violence tests.
This is objective argumentation, not subjective argumentation.
All rights originate in property ownership (ownership of ones own body included), because this is the only definition of rightful ownership that does not conflict with the accepted methods of non-violent argumentation.
Any definition of rights that falls outside of this is either violent, self-contradicting, or non-universal in nature.
Because property under this definition can be physically demonstrated, either by watching the person work the resource or looking at a receipt of purchase, this is the only way property can be defined that allows for the peaceful resolution of conflict.