I suggest that training in physical courage should be as far as possible given by teaching skill in manipulating or controlling matter, not by means of bodily contests with other human beings. The kind of courage required for mountaineering, for manipulating an aeroplane, or for managing a small ship in a gale, seems to me far more admirable than the sort required in fighting.
Source: On Education, especially in early childhood, 1926, Pt. 2： Education of character, chap. 4: Fear.
More info.:http://russell-j.com/beginner/OE04-110.HTM