I can never bring you to realize the importance of sleeves, the suggestiveness of thumb-nails, or the great issues that may hang from a boot-lace.

It has long been an axiom of mine that the little things are infinitely the most important.

When we think how narrow and devious this path of nature is, how dimly we can trace it, for all our lamps of science, and how from the darkness which girds it round great and terrible possibilities loom ever shadowly upwards, it is a bold and a confident man who will put a limit to the strange by-oaths into which the human spirit may wander.

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 fair sex is your department.

Detection is, or ought to be, an exact science, and should be treated in the same cold and unemotional manner.

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