Human beings are physical objects, according to
Hobbes, sophisticated machines all of whose functions and activities can be described and explained in purely mechanistic terms. Even thought itself, 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. (Leviathan I 1)
Human action is similarly to be explained on Hobbes's view. 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. (Leviathan I 6) 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. Hobbes nevertheless supposed that human agents are free in the sense that their activities are not under constraint from anyone else. On this compatibilist view, we have no reason to complain about the strict determination of the will so long as we are not subject to interference from outside ourselves.
(Leviathan II 21)
As Hobbes acknowledged, this account of 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 he called the "state of war," a way of life that is certain to prove
"solitary, poor, nasty, brutish, and short."
(Leviathan I 13) The only escape is by entering into contracts with each othermutually beneficial agreements to surrender our individual interests in