Human beings are physical objects, sophisticated machines all of whose functions and activities can be described and explained in purely mechanistic terms. Even thought it, therefore, must be understood as an instance of the physical operation of the human body. Sensation, for example, involves a series of mechanical processes operating within the human nervous system, by means of which the sensible features of material things produce ideas in the brains of the human beings who perceive them. Human action is similarly to be explained. Specific desires and appetites arise in the human body and are experienced as discomforts or pains which must be overcome. Thus, each of us is motivated to act in such ways as we believe likely to relieve our discomfort, to preserve and promote our own well-being. Everything we choose to do is strictly determined by this natural inclination to relieve the physical pressures that impinge upon our bodies. Human volition is nothing but the determination of the will by the strongest present desire.

Human nature emphasizes our animal nature, leaving each of us to live independently of everyone else, acting only in his or her own self interest, without regard for others. This produces what we called the state of war, a way of life that is certain to prove solitary, poor, nasty, brutish, and short. The only escape is by entering into contracts with each other mutually beneficial agreements to surrender our individual interests in order to achieve the advantages of security that only a social existence can provide. Human Society Unable to rely indefinitely on their individual powers in the effort to secure livelihood and contentment, human beings join together in the formation of a commonwealth. Thus, the commonwealth as a whole embodies a network of associated contracts and provides for the highest form of social organization. The formation of the commonwealth creates a new, artificial person to whom all responsibility for social order and public welfare is entrusted.  Of course, someone must make decisions on behalf of this new whole, and that person will be the sovereign. The commonwealth creating covenant is not in essence a relationship between subjects and their sovereign at all. Rather, what counts is the relationship among subjects, all of whom agree to divest themselves of their native powers in order to secure the benefits of orderly government by obeying the dictates of the sovereign authority.  

Since the decisions of the sovereign are entirely arbitrary, it hardly matters where they come from, so long as they are understood and obeyed universally. Genuine human freedom, maintained, is just the ability to carry out one's will without interference from others. This doesn't entail an absence of law; indeed, our agreement to be subject to a common authority helps each of us to secure liberty with respect to others. Submission to the sovereign is absolutely decisive, except where it is silent or where it claims control over individual rights to life itself, which cannot be transferred to anyone else. But the structure provided by orderly government, enhances rather than restricts individual liberty. Whether or not the sovereign is a single hereditary monarch, of course, its administration of social order may require the cooperation and assistance of others. Within the commonwealth as a whole, there may raise smaller "bodies politic" with authority over portions of the lives of those who enter into them. The sovereign will appoint agents whose responsibility is to act on its behalf in matters of less than highest importance. Most important, the will of the sovereign for its subjects will be expressed in the form of civil laws that have either been decreed or tacitly accepted. The sovereign authority will appropriately punish criminal violations of these laws by any subject. Despite his firm insistence on the vital role of the sovereign as the embodiment of the commonwealth, there are particular circumstances under which it may fail to accomplish its purpose. If the sovereign has too little power, is made subject to its own laws, or allows its power to be divided, problems will arise. Similarly, if individual subjects make private judgments of right and wrong based on conscience, succumb to religious enthusiasm, or acquire excessive private property the state will suffer. Even a well-designed commonwealth may, over time, cease to function and will be dissolved. Material man has as his end merely the preservation and promotion of his own existence. The ethical view here is known as egoism: the good is what is in my interests alone. Egoism works against social relations. It leads to competition, creating enmity among persons; to distrust, which leads us to master others for our own protection; to a lust for recognition for others, leading to revenge when it is not given. Further, each one of us is capable of subjugating or even destroying anyone else, through the use of technology, through collusion with others, etc.

Although in the state of nature, there is no right or wrong, no justice or injustice, there are still a "right of nature" and "laws of nature." The right of nature is that of self-preservation, and the only road to preserving one's self is through seeking peace and following it. Corresponding to this right is a law of nature, which enjoins us to defend ourselves. We can defend ourselves best when we give up our liberty, our "right to all things." As stated above, the social contract requires that power be conferred on an individual or assembly, the sovereign. Otherwise, there can be no confidence that surrendered rights will yield security in return. This security is needed for there to be any hope of enjoying the fruits of one's labors. Hobbes listed various rights of the sovereign, including censorship, lawmaking, judging, and making war and peace. There is never a right to revolution against the sovereign, since this is a breaking of the contract. The sovereign cannot break the contract, since the contract itself gives him the right to do what he thinks fit.