3.87. The ancients said: "Ingenuity in varying tactics depends on motherwit"; This "ingenuity", which is what we mean by flexibility, is the contribution of the intelligent commander.
4.They are rougher in manner and more difficult to polish ; but they are full of shrewdness and motherwit, and possessed of great strength of character, of which, indeed, their remarkable guttural speech is but a type.
6.After he fails, he draws his lessons, corrects his ideas to make them correspond to the laws of the external world, and can thus turn failure into success; this is what is meant by "failure is the mother of success" and "a fall into the pit, a gain in your wit".