The third law of nature proclaims that though the making of contracts is a necessary precondition to peace, we are obligated not only to make contracts but also to follow them. Out of these obligations and the consequences arising from their violation, we develop the concept of Justice. Only with the advent of the commonwealth, when such consequences can be systematized, are the concepts of justice and private property meaningful. Hobbes names sixteen additional natural laws for human conduct, totaling nineteen, that will uphold peace and together may be termed “moral philosophy.” He says that the laws may be tested, or summed up, by the golden rule: “Do not that to another, which thou wouldst not have done to yourself.”
The contract required by the most fundamental law of nature is forged and entered into by all persons. These persons can be divided into two categories: “natural persons” and “artificial persons.” Natural persons are those whose words are their own, whereas artificial persons are those whose words are those of another. The contract, as the means by which the individual wills of all natural people are joined into one unified will, then becomes a kind of artificial person, whose words are those of many others not itself. Thus, the contract, and the commonwealth it forms, is an artificial person. This great iconographic person is the Leviathan.
Hobbes leaves no doubt as to the absolute centrality of power relations in his scheme of human affairs. This emphasis is underscored by his defining many adjectives used to describe the worth of humans in terms of power. Indeed, Hobbes defines human “worth” as the measure of power possessed by an individual, in terms of how much would be exchanged to attain his power. All the relative qualities that may affect human esteem and conduct toward other people, for Hobbes, are based on the relative presence or absence of different sorts of power, and the recognition—or misrecognition—of the amount of power possessed by another person. Power’s reciprocal companion, fear, dominates Hobbes’s discussion of the state of nature. Fear both defines the state of nature and is the primary cause of its end: civil society. Most precisely, as Hobbes proclaims in De Cive, it is not mutual love between men that informs their decision to enter into society, it is their mutual fear.
In discussing the transition from state of nature to civil society, Hobbes speculates that natural laws perhaps shouldn’t rightly be called “laws,” because they don’t come from commands but rather from innate faculties of reason. But then Hobbes states that since these laws are dictated by natural reason and that nature is ruled by God, “who commandeth all things,” “law” is indeed a proper term after all. The important distinction between natural and civic laws is that natural laws are not commanded by a human power but are instead visible to all through right reason. Just the first three natural laws on their own provide all the necessary foundation for the forging of the contract that will create a civil society.