I had three sons. I told two of them to be honest, not to lie, and not to steal. I told the third son,?

a little time later, that he could both lie, if it helped him out, and he could steal, if it served a purpose. Was I wrong to do this?. The third son used these to gain ground on the other two sons. When the other two did likewise, the third son was irate. Should he be irate? Why or why not?