Human nature cannot by any means subsist, without the association of individuals
 David Hume, An Enquiry Concerning the Principles of Morals (1751). copy citation

Context

“Alliances and treaties are every day made between independent states, which would only be so much waste of parchment, if they were not found by experience to have SOME influence and authority. But here is the difference between kingdoms and individuals. Human nature cannot by any means subsist, without the association of individuals; and that association never could have place, were no regard paid to the laws of equity and justice. Disorder, confusion, the war of all against all, are the necessary consequences of such a licentious conduct.” source