logic

There's a Mr. Hyde for every happy Jekyll face, a dark face on the other side of the mirror. The brain behind that face never heard of razors, prayers, or the logic of the universe. You turn the mirror sideways and see your face reflected with a sinister left-hand twist, half mad and half sane.

You can go through your whole life telling yourself that life is logical, life is prosaic, life is sane. Above all sane. And I think it is. I've had a lot of time to think about that. And what I keep coming back to is [her] dying declaration: 'So you understand that when we increase the number of variables, the axioms themselves never change.'

Computers are composed of nothing more than logic gates stretched out to the horizon in a vast numerical irrigation system.

Crime is common. Logic is rare. Therefore it is upon the logic rather than upon the crime you should dwell.

"I don't admit that a fresh illustration is an explanation," said I with some asperity. "Bravo, Watson! A very dignified and logical remonstrance." Dr. Watson, speaking with Sherlock Holmes.

I never guess. It is a shocking habit - destructive to the logical faculty.

Ah! my dear Watson, there we come into those realms of conjecture, where the most logical mind may be at fault. Sherlock Holmes speaking with Dr. Watson.

Remember there's no such thing as a small act of kindness. Every act creates a ripple with no logical end.

Poetry, even that of the loftiest, and seemingly, that of the wildest odes, [has] a logic of its own as severe as that of science; and more difficult, because more subtle, more complex, and dependent on more and more fugitive causes. In the truly great poets... there is a reason assignable, not only for every word, but for the position of every word.

Logic is like the sword - those who appeal to it shall perish by it.