Hobbes points out that the name of "law" is deceptive, for the "laws of nature" are simply conclusions drawn from natural reason rather than mandates of governmental authority. But in the sense that these laws are required by natural reason and that nature is ruled by God, "who commandeth all things," Hobbes supposes that "law" is a proper term after all.
The contract, or covenant, required and upheld by natural law represents the persons of all involved in the construction of the contract. There are two types of persons, natural and artificial. A "natural person" is one whose words are his or her own. An "artificial person" is one whose words are those of someone else. Thus, a natural person is analogous to an "author," who is the originator of words. All the natural men in the state of nature are natural persons; their words are their own when they make a contract to escape the state of nature, and so they are authors of the contract. The contract becomes a representative of the natural people, encompassing and joining their identities; the multitude of natural persons, all authors, condense their wills into the single representation and, in so doing, the multitude becomes unified. Because the contract is a representative, or an actor, personating the words of natural persons, it fits the definition of an artificial person. The contract, symbolizing social unity, is an artificial person, and with this equation Hobbes launches the powerful iconography of the Leviathan.
Hobbes's philosophy has moved from its earlier consideration of kinetics and human nature into a controlled science of civilization. His proposals, building from elementary motion all the way into the creation of the social contract, lead to the construction of a real social science, the first sustained attempt in the history of ideas to submit human society to rigorous scientific examination. Accordingly, Hobbes is credited with the inauguration of social science in Western culture. Nevertheless, there is no real gap between Hobbes's natural science and his social science; the connection is completely seamless--or rather, the natural and the social merely represent two different points on a single spectrum.
Hobbes's philosophical program appears at a moment in history just before the Enlightenment, when a rigid distinction between the natural and the social did not yet exist. Bruno Latour has suggested that the chasm between nature and culture, which appeared during the eighteenth century, can be partly traced back to Hobbes and his debates with contemporary natural philosophers. When experimental philosophers such as Robert Boyle rejected Hobbes's radical program to reform the sciences and banned him from the English Royal Society, Hobbes was relegated to the category of social philosopher rather than natural philosopher (he was, in fact, both). The squabbles of intellectuals thus drew a line between natural and social sciences that had not existed in Hobbes's writings. Consequently, the science of nature and the science of society were perceived as having separate objects of study, and the difference between nature and society was born (see Bruno Latour, We Have Never Been Modern).
But earlier in the seventeenth century, the difference between the natural and the social was not as defined as it is for the modern world, and Hobbes's work dramatically demonstrates that nature and society can be the subjects of a single scientific endeavor. Accordingly, Hobbes's ideas are similar to two radically different modern intellectual positions, both of which collapse the distinction between nature and society but for opposite reasons. Constructivism maintains that social practices and behavior construct our knowledge of nature. Sociobiology and psychobiology, on the other hand, argue that nature and natural factors determine our social practices. Hobbes is sympathetic to both positions and expresses each at various points in Leviathan. As we have seen, Hobbes advocates the formulation of first principles by social agreement; yet, as we have also seen, he argues that human knowledge, morality, and society are all products of the fundamental kinetic motions of matter. Thus Hobbes might be simultaneously considered a sociobiologist and a social constructivist.