A Discourse on the Biography of Shang Yang衛鞅傳論
按史。秦將衛鞅遺書魏公子卬曰。往與公子驩。今爲兩國將。不可相攻。可與面相見。樂飮而罷。以安秦魏。卬以爲然。會飮。鞅伏甲攻卬滅魏軍。予以爲此甚非義也。或曰。傳有兵或用詐謀。則此亦似可。而何謂之甚非也。予曰。古人所謂用詐者。迺兵權之詐也。吾所以非之者。乃人奸之詐也。何謂兵詐。如聲東出西。左實右虛者之類是已。此亦猶未若羊祜之剋日乃戰。子犯之伐原示信者也。然兵勢或窘。則間或用之可也。夫所謂人詐者。迫人於險。紿殺降卒之類是已。若比之衛鞅。則事雖不同。其姦則類。雖爲國敗敵。吾不取也。抑又公子卬。大將也。信敵人之言。見紿被敗。何智略狹淺之至是也。吾邦俗諺亦云。敵者之言。何可聽也。是庶人之言也。公子卬爲國大將。而反不如庶人之意耶。魏使卬將兵。宜其敗也。夫詐者。一時之利也。信者。久長之計也。
Looking into history, I find that Shang Yang (商鞅), a general of Qin (秦), sent a letter to Prince Ang (卬) of Wei (魏), saying: "In days past I passed happy times with you, my prince, and now that we have become the generals of two states we cannot attack each other. Let us meet face to face, drink in good cheer and break up, and so set Qin and Wei at ease." Ang thought this well, and they gathered and drank; but Shang Yang had hidden armored soldiers, and he struck Ang and destroyed the army of Wei. I hold this to have been a most unrighteous act.
Someone said: "It is handed down that in war one may sometimes use deceit; this too would seem allowable, so why call it so very wrong?"
I said: What the ancients called using deceit is the deceit that follows the shape of circumstances in handling troops; what I call wrong is the deceit of a crooked character. What is the deceit of war? Making a noise in the east and coming out in the west, making the left solid and the right empty, and the like — this is it. Even this falls short of Yang Hu (羊祜) fixing a day and then fighting, or Zifan (子犯) showing good faith in attacking Yuan (原). Still, when the shape of a campaign is straitened, it is allowable to use it now and then.
Now what is called the deceit of a man is driving men into a defile, or deceiving and killing soldiers who have surrendered, and the like. Set beside Shang Yang, the affair is not the same, yet the crookedness is alike. Even if he crushed the enemy for his state's sake, I do not approve of it.
Then too, Prince Ang was a commander in chief. He trusted the enemy's words, was deceived, and was defeated; how did the narrowness and shallowness of his wit and planning come to such a pass? Even a proverb of our own country says, "How can one listen to an enemy's words?" — and that is the speech of ordinary people. Was Prince Ang, made commander in chief of his state, in the end not even the equal of an ordinary man's thinking? Wei let Ang take command of its troops; it was fitting that it should be defeated.
Now deceit is the gain of one moment, and good faith is a long and lasting plan.
Interlinear notes 1
The source text writes Wi Ang (衛鞅). He was so called because he was born in the state of Wi (衛), but in Korean that sounds the same as the state of Wi (魏) which also appears in this piece, so the widely used Sang Ang — Shang Yang (商鞅) — has been written instead. — translator