Problems may be solved in the study which have baffled all those who have sought a solution by the aid of their senses. To carry the art, however, to its highest pitch, it is necessary that the reasoner should be able to use all the facts which have come to his knowledge; and this in itself implies, as you will readily see, a possession of all knowledge, which, even in these days of free education and encyclopaedias, is a somewhat rare accomplishment.

Why should you go further in it? What have you to gain from it?''What, indeed? It is art for art's sake, Watson. I suppose when you doctored, you found yourself studying cases without thought of a fee?''For my education, Holmes.''Education never ends, Watson. It is a series of lessons with the greatest for the last.

It is a capital mistake to theorize before you have all the evidence. It biases the judgment.

It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts.

Philosophy, astronomy, and politics were marked at zero, I remember. Botany variable, geology profound as regards the mud stains from any region within fifty miles of town, chemistry eccentric, anatomy unsystematic, sensational literature and crime records unique, violin player, boxer, swordsman, lawyer, and self-poisoner by cocaine and tobacco.