So the varnasrama system is a system of interface between material desires and necessities, and spiritual necessities, by engaging people according to their proclivity and ability and focusing that, channeling that, toward Krishna – understanding that everything here is temporary and therefore although our present proclivity may be towards producing goods or serving others, our real necessity of life is to understand Krishna.
Lecture on SB 3.6.32 – About the Four Varnas – Vyasa Puja 2008 – 5th Jan'08 – Tirupati