In this section of De Cive (by far the most important in the book) Hobbes makes the argument about man in the state of nature that he most famously made in Leviathan. He claims that in the state of nature, men would contend and fight with one another, because of their inherent greed, fear of one another, and the natural desire of self-preservation:
[M]any men at the same time have an Appetite to the same thing; which yet very often they can neither enjoy in common, nor yet divide it; whence it followes that the strongest must have it, and who is strongest must be decided by the Sword.
In other words, the state of nature would be a constant state of warfare, one in which everyone fought against each other to gain and protect possessions by force. It would be, as he famously put it, a "war of all against all." Because people wanted to be safe, however, they would enter into civil society, a point he makes in the second section of "Liberty" and would expand upon later in Leviathan.