The idea that no gentleman ever swears is all wrong. He can swear and still be a gentleman if he does it in a nice and benevolent and affectionate way.
Our civilization has decided that determining the guilt or innocence of men is a thing too important to be trusted to trained men. When it wants a library catalogued, or the solar system discovered, or any trifle of that kind, it uses up its specialists. But when it wishes anything done which is really serious, it collects twelve of the ordinary men standing round. The same thing was done, if I remember right, by the Founder of Christianity.