Education never ends, Watson. It is a series of lessons, with the greatest for the last.

So complex is the human spirit that it can itself scarce discern the deep springs which impel it to action.

It is fortunate for this community that I am not a criminal.

I suppose I shall have to compound a felony as usual.

A client is to me a mere unit, a factor in a problem.

The most winning woman I ever knew was hanged for poisoning three little children for their insurance-money, and the most repellent man of my acquaintance is a philanthropist who has spent nearly a quarter of a million upon the London poor.

If in 100 years I am only known as the man who invented Sherlock Holmes then I will have considered my life a failure.