What do we call love, hate, charity, revenge, humanity, forgiveness? Different results of the master impulse, the necessity of securing one's self-approval.
A powerful agent is the right word. Whenever we come upon one of those intensely right words in a book or newspaper the resulting effect is physical as well as spiritual, and electrically prompt.
I never made a success of a lecture delivered in a church yet. People are afraid to laugh in a church. They can't be made to do it in any possible way.