" What is the human purpose in society? It is to exchange one good for another good more desired. Putting it on a personal basis, it is a matter of benefiting yourself by getting something you desire from another person who, at the same time, benefits himself by getting something that he desires from you. The object of such contacts is the peaceful exchange of benefits, mutual aid, co-operation – for each person’s gain. The incalculable sum of all these meetings is human society, which is simply all the individual human actions that express the brotherhood of man. "

― , The Mainspring of Human Progress