Everything is made for a purpose, and naturally moves toward that purpose. Where something finds its purpose, there it finds its good. For rational beings like us, that good is society. We are made for community — this has been proven many times. Can anyone really doubt that lesser things serve greater things? That the best things are made to work together? Things with souls are better than things without souls. And among those with souls, rational beings are the best.
Again, that which everything is made for, he is also made unto that, and cannot but naturally incline unto it. That which anything doth naturally incline unto, therein is his end. Wherein the end of everything doth consist, therein also doth his good and benefit consist. Society therefore is the proper good of a rational creature. For that we are made for society, it hath long since been demonstrated. Or can any man make any question of this, that whatsoever is naturally worse and inferior, is ordinarily subordinated to that which is better? and that those things that are best, are made one for another? And those things that have souls, are better than those that have none? and of those that have, those best that have rational souls?