The purpose of a social contract theory is to show that members of a society have reasons to support and respect the fundamental social rules, laws, institutions and/or principles of that society. To simplify, this is the public justification, that is, to “determine whether a particular regulation is legitimate and therefore fair” (D`Agostino, 1996, 23). The ultimate goal of state-oriented social contract theories is to show that a political system can meet the challenge raised by Alexander Hamilton in federalist No. 1, namely whether “men are truly capable or not of establishing good government by reflection and choice, or whether they are destined to be forever destined to depend on accident and violence on their political constitutions” (Hamilton 1788). Moreover, it appears that David Gauthier argues that any system of moral coercion must be justified against those to whom it must be applied. “What moral theory,” Gauthier asks, “can it ever serve a useful purpose, unless it can show that all the duties it recommends are truly supported in everyone`s reason?” (1986, 1). Hobbes` political theory is best understood when it enters into two parts: his theory of human motivation, psychological selfishness, and his theory of social contract, based on the hypothetical state of nature. Hobbes has above all a particular theory of human nature that leads to a particular vision of morality and politics, as developed in his philosophical masterpiece Leviathan, published in 1651. The scientific revolution, with its important new discoveries, which the universe could be described and predicted in accordance with the universal laws of nature, strongly influenced Hobbes. He tried to provide a theory of human nature that would be equated with discoveries in the sciences of the inanimate universe. His psychological theory is therefore informed by the mechanism, the general opinion that everything in the universe is produced by nothing but matter in motion. According to Hobbes, this extends to human behavior. Human macro-behaviors can be well described as the effect of certain types of micro-behaviors, although some of these latter behaviors are invisible to us.
Behaviours such as walking, speech, etc. are therefore created in us by other actions. And these other actions are themselves caused by the interaction of our body with other bodies, human or otherwise, which create in us certain chains of causes and effects, and which end up leading to human behavior that we can clearly observe. We, including all our actions and decisions, are then, according to this conception, as explicable in terms of universal laws of nature as the movements of celestial bodies. The gradual disintegration of memory can, for example, be explained by inertia. As we are presented with more and more sensory information, the delay of previous impressions slows down over time.