Autobiography

...never accepting half-solutions of difficulties as complete; never abandoning a puzzle, but again and again returning to it until it was cleared up; never allowing obscure corners of a subject to remain unexplored, because they did not appear important; never thinking that I perfectly understood any part of a subject until I understood the whole.

A pupil from whom nothing is ever demanded which he cannot do, never does all he can.

He [father] was fond of putting into my hands books which exhibited men of energy and resource in unusual circumstances, struggling against difficulties and overcoming them...