You know my method. It is founded upon the observation of trifles.

You know my methods. Apply them.

Beyond the obvious facts that he has at some time done manual labour, that he takes snuff, that he is a Freemason, that he has been in China, and that he has done a considerable amount of writing lately, I can deduce nothing else.

No man burdens his mind with small matters unless he has some very good reason for doing so.

To a great mind, nothing is little,' remarked Holmes, sententiously.

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