Which is it to-day," I asked, "morphine or cocaine?" — Sherlock Holmes

"I never make exceptions. An exception disproves the rule."

"But the Solar System!" I protested. "What the deuce is it to me?" he interrupted impatiently; "you say that we go round the sun. If we went round the moon it would not make a pennyworth of difference to me or to my work."

"I had neither kith nor kin in England, and was therefore as free as air — or as free as an income of eleven shillings and sixpence a day will permit a man to be. Under such circumstances I naturally gravitated to London, that great cesspool into which all the loungers and idlers of the Empire are irresistibly drained. There I stayed for some time at a private hotel in the Strand, leading a comfortless, meaningless existence, and spending such money as I had, considerably more freely than I ought"

"His ignorance was as remarkable as his knowledge. Of contemporary literature, philosophy and politics he appeared to know nothing. Upon my quoting Thomas Carlyle, he inquired in the naivest way who he might be and what he had done. My surprise reached a climax, however, when I found incidentally that he was ignorant of the Copernican Theory and of the composition of the Solar System. That any civilized being in this nineteenth century should not be aware that the earth traveled round the sun appeared to me to be such an extraordinary fact that I could hardly realize it."

"The theories which I have expressed there, and which appear to you to be so chimerical, are really extremely practical — so practical that I depend upon them for my bread and cheese."

"They say that genius is an infinite capacity for taking pains," he remarked with a smile. "Its a very bad definition, but it does apply to detective work."