A candid consideration of his own experiments must guide him in the selection of the better methods, in the discrimination of the more appropriate subject-matter, in the avoidance of his own peculiar failings, and in the cultivation of his own peculiar strength.

The technical career of the master is up to a certain point always a matter of growth.

The technical career of the second-rate man is always a matter of degeneration or at best of repetition.

The former brings with it its own salient and special form of enlightenment based upon the intellectual power to criticise his own experience and the moral power to act on his own acquired insight.

To this extent he becomes more of a man by the very process of becoming more of a master.
The intellectual power required to criticise one's own experience with a formative result will of course vary considerably in different occupations.