light. "Never tell a lie--except for practice," is less successful than
the more popularly known "When in doubt, tell the truth." Out of the
latter maxim he succeeded in extracting a further essence of humour. He
admitted inventing the maxim, but never expected it to be applied to
himself. His advice, he said, was intended for other people; when he
was in doubt himself, he used more sagacity! Mark Twain has made no
more delightful epigram than that one in which he recognizes that a lie,
morally reprehensible as it may be, is undoubtedly an ever present help
in time of need: "Never waste a lie. You never know when you may need
it."

Sometimes in a humorous, sometimes in a grimly serious way, Mark Twain
was fond of drawing the distinction between theoretical and practical
morals. Theoretical morals, he would point out, are the sort you get on
your mother's knee, in good books, and from the pulpit. You get them
into your head, not into your heart. Only by the commission of crime
can anyone acquire real morals. Commit all the crimes in the decalogue,
take them in rotation, persevere in this stern determination--and after
awhile you will thereby attain to moral perfection! It is not enough to
commit just one crime or two--though every little bit helps. Only by
committing them all can you achieve real morality! It is interesting to
note this distinction between Mark Twain, the humorous moralist, and
Bernard Shaw, the ethical thinker. Each teaches precisely the same
thing--the one not even half seriously, the other with all the sharp
sincerity of conviction. Shaw unhesitatingly declares that trying to be
wicked is precisely the same experiment as trying to be good, viz., the
discovery of character.

The range of Mark Twain's humour, from the ludicrous anecdote with
comically mixed morals to the profound parable with grimly ironic