Sun Tzŭ said: The art of war is of vital importance to the State.

2. It is a matter of life and death, a road either to safety or to ruin. Hence it is a subject of inquiry which can on no account be neglected.

3. The art of war, then, is governed by five constant factors, to be taken into account in one’s deliberations, when seeking to determine the conditions obtaining in the field.

4. These are: (1) The Moral Law; (2) Heaven; (3) Earth; (4) The Commander; (5) Method and discipline.

[It appears from what follows that Sun Tzŭ means by "Moral Law" a principle of harmony, not unlike the Tao of Lao Tzŭ in its moral aspect. One might be tempted to render it by "morale," were it not considered as an attribute of the ruler in § 13.]

5, 6. The Moral Law causes the people to be in complete accord with their ruler, so that they will follow him regardless of their lives, undismayed by any danger.

[Tu Yu quotes Wang Tzŭ as saying: "Without constant practice, the officers will be nervous and undecided when mustering for battle; without constant practice, the general will be wavering and irresolute when the crisis is at hand."]

7. Heaven signifies night and day, cold and heat, times and seasons.

[The commentators, I think, make an unnecessary mystery of two words here. Meng Shih refers to "the hard and the soft, waxing and waning" of Heaven. Wang Hsi, however, may be right in saying that what is meant is "the general economy of Heaven," including the five elements, the four seasons, wind and clouds, and other phenomena.]

8. Earth comprises distances, great and small; danger and security; open ground and narrow passes; the chances of life and death.