It is foolish, generally speaking, for a philosopher to set fire to another philosopher in Smithfield market because they do not agree in their theory of the universe. That was done very frequently in the Middle Ages, and it failed altogether in its object. But there is one thing that is infinitely more absurd and unpractical than burning a man for his philosophy. This is the habit of saying that his philosophy does not matter, and this is done universally in the twentieth century, in the decadence of the great revolutionary period. General theories are everywhere contemned; the doctrine of the Rights of Man is dismissed with the doctrine of the Fall of Man. Atheism itself is too theological for us today. Revolution itself is too much of a system; liberty itself is too much of a restraint. We will have no generalizations. Mr. Bernard Shaw has put the view in a perfect epigram: "The golden rule is that there is no golden rule." We are more and more to discuss details in art, politics, literature. A man's opinion on tramcars matters; his opinion on Botticelli matters; his opinion on all things does not matter. He may turn over and explore a million objects, but he must not find that strange object, the universe; for if he does he will have a religion, and be lost. Everything matters--except everything.
(Heretics. Introductory Remarks.)
What is he doing here, again? He is contrasting the zeal of the Middle Ages, which resulted in the burning of heretics, with the current refusal to come to any rules, at all. As silly as the former approach may seem now, we seem to have overcompensated to a point where we will have no generalizations, no doctrines, no golden rules--except that there is no golden rule--no theory of the universe, no religion.
I am not sure if that is the same as existentialism. Make up your own individual meaning. Probably.
What do I know.