The book expounds on how one should run a state. The main points are to keep the people occupied with agriculture, war, and nothing else. Trade should be heavily taxed to avoid people gaining money and merit by means other than farming and fighting. The law should provide far more punishments than rewards, and the punishments for minor offenses should be severe so as to discourage anyone from Jumping Off the Slippery Slope into more serious crimes. However, there are some palatable arguments; the authors maintain that promotion and advancement should be based entirely on merit, and have nothing to do with one's family or other circumstances. They also advocate that all people, from the Emperor to the lowest peasant, should be treated equally by the law. Unfortunately Lord Shang later bit the end of this when he was painfully executed, along with nine generations of his family, by the new king for having previously advocated treating him as a common criminal. Shang attempted to flee this fate but was apprehended when he was unable to stay at any inns without identifying himself, also a law that he had implemented.
In contrast to more prevalent 'Confucian' thought from thinkers such as Mencius, the Legalists believed that humans are naturally lazy, corrupt, petty, and wicked, hence the emphasis on punishment to be found throughout the book.
Also note that Legalism as actually practiced by Qin could differ considerably than Legalism as espoused by the book. When looking at Qin history, it's important to remember that every traditional work of history covering it has been written by someone with a good reason to villainize it (e.g. enemy state, successor state, member of the gentry...) and archaeological evidence from the last century paints a much more complex picture. Qin legal codes from later in the Warring States decreed a wide range of punishments, ranging from fines to state slavery to painful death, and contain some ideas much more sympathetic to modern eyes, such as forbidding wife-beating, placing strict regulations on interrogation techniques, and forcing people to help the victim of a crime in progress or be punished themselves, that were dropped for two thousand years once Qin fell. We also have bamboo slip letters written to and by common soldiers, suggesting that learning wasn't as suppressed in Qin as it's often claimed.
The Book of Lord Shang provides examples of:
- All Crimes Are Equal: Advocates using this. Didn't work out so well in practice, for reasons highlighted in Disproportionate Retribution below.
- Culture Police: Shang thinks they're a jolly good idea. It's probably no coincidence that Qin Shi Huangdi, whose policies were heavily informed by Legalist thinkers like Shang, infamously ordered all non-technical writing in his country burned.
- Decadent Court:
- The authors are very much against this. People should only gain prestige by excelling in agriculture and war, not by currying the ministers' or Emperor's favor, not to mention nepotism.
- On a more meta level, as harsh as Lord Shang was to commoners, what really got him killed was daring to be equally harsh to the nobility and ruling family, and replacing the traditional aristocratic mode of governance with centralized bureaucratic and meritocratic rule.
- Disproportionate Retribution: Intended to make the penalties of lesser crimes so horrible that no one would even contemplate greater crimes. Backfired when tried by the Qin dynasty, where it just created a huge mass of men who suddenly had nothing to lose in backing a rebellion. There isn't really a way to top gruesome death as a punishment.
- Dystopia Is Hard: The sheer amount of effort required to rigidly control people to the extent posited in the book seems a lot harder than simply keeping them well-fed and happy would be, at least to modern eyes. Given the chaos of the Warring States, however, it should be noted that even philosophers grouped under Confucians by later generations wrote at least some grudging praise for Qin's orderly, meritocratic governance.
- Gray-and-Grey Morality: Lord Shang didn't believe in objective goodness; what mattered was obedience to the law.
- Hobbes Was Right: Shang was a firm believer in the notion that people were bastards that could only be kept in line with an iron hand. Ironically, he was executed over personal and petty grudge the new king had against him.
- Hoist by His Own Petard: Shang Yang met his end under a punishment that he himself formulated into Qin law, one reserved for law enforcers who broke the law themselves, when he ended up being accused of treason by the new king of Qin (in revenge for the abuse Shang heaped on the king as his tutor back when he was still the crown prince) and Shang and his entire family were sentenced to death. And even better, when he tried to hide out in a hotel to escape the above fate, he was refused, as the strict laws he had enacted in Qin while in power made it illegal for a hotel owner to admit a guest without proper identification. He was later caught, followed by drawing and quartering by chariot.
- And the Qin dynasty itself fell victim to the Legalist logic of blind obedience and horrible punishment for any misconduct. When All Crimes Are Equal and every crime is punishable by death, people have only one choice when they mess up: die or revolt. And once the revolt starts, there is no stopping, because the blindly followed law offers no other punishment than painful execution.
- Honor Before Reason: The authors strenuously objected to this mode of conduct, citing it as one of the main reasons no-one had yet successfully united China.
- Humans Are Bastards: Among other things.
- Misaimed Fandom: When Shang argues that the army should be at war whenever possible, he cites The Art of War in favor of his argument, apparently having missed the many parts where Sun Tzu specifically said that it is always and without exception better to resolve a conflict or dispute by diplomacy than by combat.
- Silly Reason for War: Shang advises that the army should be at war as much as possible to prevent the soldiers falling victim to such "parasites" as virtue and care for the elderly.
- Sins of Our Fathers: Since it is more important for law enforcers to obey the law than anyone else, it is advised that if they break it, then their children should be punished as well.
- And ironically, Shang and his family would suffer this very punishment when he was convicted of treason against King Huiwen of Qin (see Hoist by His Own Petard above). The practice of family extermination, called the "Nine Exterminations" for the nine categories that family members would be put into, would be reserved for only the most heinous of offenses against the state (treason and rebellion) in feudal China until its eventual abolition by the Qing Dynasty in 1905.
- Utopia: This is how a China ruled by Legalist principles is presented. However, to many eyes and like many pre-modern examples, Shang's vision looks positively dystopic.
- Won the War, Lost the Peace: Since peace is to be outright avoided under Shang's philosophy, it's hard to keep the government together without a war on. Sure enough, the Qin dynasty basically ended this way.
- Working-Class People Are Morons: The authors didn't just invoke this, they intended to enforce it.
- Yes-Man: Repeatedly warned against.