All of these are from the first book, which deals with the origin and nature of laws.
...even most of them (brutes, animals) are more attentive than we to self-preservation, and do not make so bad a use of their passions.
Such a being (man) might every instant forget his Creator; God has therefore reminded him of his duty by the laws of religion. Such a being is liable every moment to forget himself; philosophy has provided against this by the laws of morality. Formed to live in society, he might forget his fellow-creatures; legislators have, therefore, by political and civil laws, confined him to his duty.
As soon as man enters into a state of society he loses the sense of his weakness; equality ceases, and then commences the state of war.
The strength of individuals cannot be united without a conjunction of all their wills.