The concept of natural right is different from the concept of natural rights. Book 5 of the Ethics is the most relevant on this topic, but it is also the most frustrating.
Before we get to the concept of natural right, let’s dispense with the definition of natural rights. Rights are something we humans possess. It is like a trump card that we are able to use against governments, and individuals. These rights are something inalienable to humans and hence, cannot be sold or traded.
Now, we have already discussed that which is just by nature and that which is just by convention. In the context of this discussion is where Aristotle raises the question of natural right. The question of justice is raised in the debate with the city, and its defenders, of the source of justice. Socrates’ turn to a consideration of the human things, and identification of the law with nature, is essential in the discovery of what we now know as “classical natural right.”
Nature is the ground, or the source, of the “isness” of things. One teaching of classical natural right is the “critique of hedonism,” which was brought forth by the conventionalists (Leo Strauss, NR&H, 126). To wit:
“Different kinds of beings seek or enjoy different kinds of pleasure: the pleasures of an ass differ from the pleasures of a human being. The order of the wants of a being points back to the natural constitution” (ibid).
A being approaches the good as he/she does his/her work well. To know what is good for humans we must know what is naturally good for them. This supplies the basis of natural right (ibid, 127). The major books of political philosophy are most concerned with politics and justice. The concern with the best regime is essentially a concern with natural right (ibid, 144). In our modern world, Strauss goes on to write, natural right has been blurred under the twin assaults known as egalitarianism and biblical faith. Regardless, we can still understand or deduce what natural right is.
To cut to Aristotle–and really one part of one chapter in Book 5–he makes the seemingly audacious claim that natural right is a part of political right. In other words, strict natural right is too much to take, and hence, must be diluted in the city so as to not be too shocking. We saw this in the Republic in the allegory of the cave. That natural right is a part of political right (or convention), is perhaps less venturesome when compares to the next statement at 1134b30. He asserts that all right is changeable. Now, what to make of this? Perhaps we should quote from the Ethics at length:
Of political justice part is natural, part legal, natural, that which everywhere has the same force and does not exist by people’s thinking this or that; legal, that which is originally indifferent, but when it has been laid down is not indifferent, e.g. that a prisoner’s ransom shall be a mina, or that a goat and not two sheep shall be sacrificed, and again all the laws that are passed for particular cases, e.g. that sacrifice shall be made in honour of Brasidas, and the provisions of decrees. Now some think that all justice is of this sort, because that which is by nature is unchangeable and has everywhere the same force (as fire burns both here and in Persia), while they see change in the things recognized as just. This, however, is not true in this unqualified way, but is true in a sense; or rather, with the gods it is perhaps not true at all, while with us there is something that is just even by nature, yet all of it is changeable; but still some is by nature, some not by nature. It is evident which sort of thing, among things capable of being otherwise, is by nature, and which is not but is legal and conventional, assuming that both are equally changeable. And in all other things the same distinction will apply; by nature the right hand is stronger, yet it is possible that all men should come to be ambidextrous. The things which are just by virtue of convention and expediency are like measures; for wine and corn measures are not everywhere equal, but larger in wholesale and smaller in retail markets. Similarly, the things which are just not by nature but by human enactment are not everywhere the same, since constitutions also are not the same, though there is but one which is everywhere by nature the best. Of things just and lawful each is related as the universal to its particulars; for the things that are done are many, but of them each is one, since it is universal.
It seems contradictory: natural right is changeable, but above, he states that it is not changeable: fire burns here and in Persia. Fire is the same everywhere. The basic principles of fire are not different, or changed, in the U.S. v. England. This concept has the same “force” or “power” everywhere. But what messes people up is convention. It remains that there are certain things that are different between countries/cities. What to make of this?
Aristotle puts on a false countenance claiming that all things human are changeable even while there are things that do not change! In what way is natural right changeable? Let us turn to Strauss to make it clear:
Aristotle does not primarily think of any general propositions, but rather of concrete decisions. All action is concerned with particular situations. Hence justice and natural right reside, as it were, in concrete decisions rather than general rules… A law which solves justly a problem peculiar to a given country at a given time may be said to be just to a higher degree than any general rule of natural law which, because of its generality, may prevent a just decision in a given case. In every human conflict there exists the possibility of a just decision based on full consideration all the circumstances, a decision demanded by the situation. Natural right consists of such decisions. Natural right thus understood is obviously mutable (Strauss, NR&H, 159).
It would perhaps be best to consider it this way: in every political decision there is a most just choice to make given the circumstances. Aristotle does not contend that decision are made without a concern for the universal. Quite the opposite. In light of the universal, there resides a best possible decision [1135a5-10]. Indeed, this means, that someone who makes no decision based on not realizing a universal law/claim is acting without a regard for justice.
This is the high point of the Ethics. The discussion of natural right comes at the center of the book. The rest of the book gets back to the virtues–friendship, moral excellence, intellectual excellence, etc. That descent will come soon enough. For the moment we rest at the summit.