"The powers inherent in man are his intelligence and his physical capacity for work. Those which arise from the condition of society consist of the capacity to divide up labour and to distribute different jobs amongst different People ... and the power to exchange mutual services and the products which constitute these means. The motive which impels a man to give his services to another is self -interest- he requires a reward for the services rendered. The right of exclusive private property is indispensable to the establishment of exchange amongst men... Exchange and division of labour reciprocally condition each other."