His ignorance was as remarkable as his knowledge. Of contemporary literature, philosophy and politics he appeared to know next to nothing... 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.

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.

Circumstantial evidence is occasionally very convincing, as when you find a trout in the milk, to quote Thoreau's example.

By a man's finger-nails, by his coat-sleeve, by his boots, by his trouser-knees, by the callosities of his forefinger and thumb, by his expression, by his shirt-cuff — By each of these things a man's calling is plainly revealed. That all united should fail to enlighten the competent inquirer in any case is almost inconceivable. You know that a conjurer gets no credit when once he has explained his trick; and if I show you too much of my method of working, you will come to the conclusion that I am a very ordinary individual after all.

I have frequently gained my first real insight into the character of parents by studying their children.

On general principles, it is best that I should not leave the country. Scotland Yard feels lonely without me, and it causes an unhealthy excitement among the criminal classes.

The love of books is among the choicest gifts of the gods.