XXI.

A city does not need all the food a province produces, but that much food is far from enough to feed the whole country; it needs all the food the country can produce. The strength of an individual is nothing compared with collective strength.

XXII.

What to do to beat your equal in battle? Attack him where he is most vulnerable with concentrated force and victory will be yours. A piece of wood with a sharp end can break another piece of wood that is just as hard as the wood you use to attack.

XXIII.

Success in life depends not only on wisdom and ability but also on time and opportunity. Given no time and opportunity, wisdom and ability cannot come into play. Only when all the elements meet will success be the result. This is the true way of achieving success.

XXIV.

Intellectual and material resources work in opposite ways. Intellectual resources are limitless; the more they are tapped, the broader they grow in scope. Impermanent in nature and limited in quantity, material resources last but a short time, and the more they are consumed the sooner they are exhausted. The truth is that the former is non-quantifiable and thus infinite and everlasting while the latter is quantifiable and therefore diminishing and exhaustible.

XXV.

Exercise caution when everything goes your way; persevere in what you do when nothing goes your way. In the former case, lack of caution results in disasters; in the latter case, perseverance will never go unrewarded.