Chesterton on Slang . . . and Psychology . . . sort of

From G.K.'s Weekly, May 9, 1931 via the May/June 2019 edition of Gilbert! (which appears to have gotten its exclamation point back)

That is the sort of slang that is really weakening language and literature in America.  It is the weary tossing about at tenth hand of certain words supposed to belong to a science of psychology; a psychology which I suspect that the psychologists do not understand and I know that the journalists do not understand.  There was an even worse example in the case of the quarrel that arose round the alleged attack on American culture by Mr J.B. Priestley  An American lady, writing a spirited reply to Mr Priestley, poured scorn upon what she call the “sadistic” cowardice of Americans in submitting to such criticism.  What she imagined the word “sadistic” to mean the devil only knows; the devil being the only person who ought to be interested in it.  All over American magazines, even the most intelligent and interesting articles, there is sprinkled this silly slang of popular science; a welter of long words that are either utterly unmeaning, or unmeaning where they are used, or mean something entirely different.  In so far as they had any relation to psychology, or in so far as psychology had any relation to reason, the only possible effect they could have would be to provide the future with a widespread psychological study of softening of the brain.