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.
Mark TwainThere is not an acre of ground on the globe that is in possession of its rightful owner, or that has not been taken away from owner after owner, cycle afer cycle, by force and bloodshed.
Mark TwainThe waves most washed me off the raft sometimes, but I hadn't any clothes on, and didn't mind.
Mark Twain