It is there shown, that an emotion can only be restrained by an emotion stronger than, and contrary to itself, and that men avoid inflicting injury through fear of incurring a greater injury themselves.
On this law society can be established, so long as it keeps in its own hand the right, possessed by everyone, of avenging injury, and pronouncing on good and evil; and provided it also possesses the power to lay down a general rule of conduct, and to pass laws sanctioned, not by reason, which is powerless in restraining emotion, but by threats (IV.xvii.

note).

Such a society established with laws and the power of preserving itself is called a State, while those who live under its protection are called citizens.

We may readily understand that there is in the state of nature nothing, which by universal consent is pronounced good or bad; for in the state of nature everyone thinks solely of his own advantage, and according to his disposition, with reference only to his individual advantage, decides what is good or bad, being bound by no law to anyone besides himself.
In the state of nature, therefore, sin is inconceivable; it can only exist in a state, where good and evil are pronounced on by common consent, and where everyone is bound to obey the State authority.

Sin, then, is nothing else but disobedience, which is therefore punished by the right of the State only.