For I saw that those who follow these pursuits carelessly
 suffer loss, and I discovered that those who devote
 themselves earnestly to them accomplish them more
 quickly, more easily and with more profit. I think
 that if you would elect to learn from these, you too
 with God’s favour would turn out a clever man of
 business. Socrates , 
 exclaimed Critobulus on hearing this, I don’t
 intend to let you go now, until you have proved to
 my satisfaction what you have promised in the
 presence of our friends here to prove. 
 Well then, said
 Socrates ,
 what if I prove to your satisfaction, Critobulus,
 to begin with, that some men spend large sums in
 building houses that are useless, while others build
 houses perfect in all respects for much less? Will
 you think that I am putting before you one of the
 operations that constitute estate management? 
 Yes, certainly.