'Under Bartitsu is included boxing, or the use of the fist as a hitting medium, the use of the feet both in an offensive and defensive sense, the use of the walking stick as a means of self-defence. Judo and jujitsu, which are secret styles of Japanese wrestling, (I) would call close play as applied to self-defence.
In order to ensure, as far as it is possible, immunity against injury in cowardly attacks or quarrels, (one) must understand boxing in order to thoroughly appreciate the danger and rapidity of a well-directed blow, and the particular parts of the body which are scientifically attacked. The same, of course, applies to the use of the foot or the stick.

Judo and jujitsu were not designed as primary means of attack and defence against a boxer or a man who kicks you, but are only to be used after coming to close quarters, and in order to get to close quarters it is absolutely necessary to understand boxing and the use of the foot.'
Barton-Wright