The context of natural rights and natural law theories is very important to understanding what Rousseau is doing. The two, related debates are complex, and began with ancient and medieval thinkers. Among the more recent thinkers that Rousseau refers to, Hobbes and Grotius are the most important. Essentially, a natural right is a claim that all people have over others by virtue of being human, such as a right to have, or to do, something. Natural rights are not granted or instituted by society, but are created by God or Nature. Similarly, natural laws are rational regulations that compel all people to act in a certain way, and are generally seen as commands from God or Nature to be obeyed by man. Hence the prize question Rousseau is answering is about whether God or Nature commands that people should be unequal. An example of a natural law is the command to seek peace with other people at every opportunity whereas an example of a natural right is the right to self-preservation. Natural right and natural law are not interchangeable, but together were often seen as providing a basic framework of rights and duties that could be used to found a political society. The point is to avoid conflict by establishing an uncontroversial basis for people to join together. However, as Rousseau points out, no one can agree on what rights and duties were natural or basic. The second problem is that modern thinkers believe that only a rational creature can have natural rights. This represents a raw deal for the animals, but also a problem for Rousseau, who goes on to argue that natural man and animals are, in fact, alike.
Rousseau's key point is that natural rights and laws mean nothing if we do not understand the nature of man. There must be a correlation between the two for natural laws to mean anything. Therefore, to understand what this nature is, we have to take reason out of the equation entirely, as man in his original condition may not have been a rational creature. We need basic concepts, or principles, on which to base a theory of man—concepts that have nothing to do with reasoning. In designating self-preservation and pity as these principles, he selects two apparently conflicting concepts. The desire to preserve one's own life is a standard of natural rights theories, discussed by both Hobbes and Grotius, but pity is a more novel concept. Whilst one principle pulls man towards others, the other directs him towards himself. Rousseau argues that there is no contradiction between the two. This is a key theme that will be developed later in the Discourse.
Also important is the reference to the natural rights of animals. Rousseau argues not that animals have all the rights that humans do, but only that to harm another sentient creature is universally wrong. It introduces a central point made in Part One of the Discourse, that man in his natural state is merely an animal, and shares all of an animal's central characteristics.