How do you recognise a criminal? How do you make sure that innocents are not targeted or even inconvenienced by law enforcement? How do you balance control and freedom? These are some of the questions that Psycho Pass poses, from the point of view of Japan's current society, with its emphasis on conformity, and its very low tolerance for any kind of deviation from the accepted way of life.
It's the 22nd century, and the Sybil System can detect the state of mind of every person, optimising their lives for happiness, by for example suggesting their best career options, but also calculating their propensity for crimes. The whole law enforcement system is based on this "crime coefficient", and the police is equipped with special guns called "Dominators" that will paralyse potential criminals, or kill them outright if their coefficient is too high. No arrest, no tribunals: if the Sybil says someone's a criminal, that's enough.
This rather direct and violent approach tends to destabilise minds, so the police uses Enforcers, potential criminals that have been selected by the system, to do most of the hunting down of other criminals. Inspectors are tasked with detective work, and supervision of the Enforcers.
Tsunemori Akane joins the police straight out of school as an Inspector, and has to find her way among her colleagues and subordinates, wrestle with moral questions, and avoid letting her crime coefficient rise.
UROBUCHI Gen (虚淵 玄) of Nitro+ has written a story with layers: the "good" characters are not always as good as you'd expect, and the "bad" characters have motivations that at the very least make sense to them, and in some cases are indistinguishable from those that in other stories are attributed to heroes. This is not a good-vs-evil plot.
There are some issues. The worldbuilding has holes, that may have been put there deliberately to provide the hooks for plot twists and for more interesting character development and moral questioning, but still undermine the consistency of the setting. Some parts of the story feel a bit paint-by-numbers, and, especially in the first few episodes, there's just too much expository infodumping. But I think that it's all forgivable, given the overall result.
I've seen Psycho Pass compared to Ghost in the Shell, and I can see the similarities: they're both set in a technocratic future, focusing on police work. The questions they ask are very different though: GitS (especially the movie version) asks "what's the essence of humanity, and what would it take for you to recognise a non-human life form as human in spirit?"; Psycho Pass asks "what are you prepared to sacrifice in the name of social stability and average contentment?". Neither work provides answers, but they definitely provide food for thought.
As a note on the English edition, the translation appears to do justice to the complex dialogues and ideas, which is sadly unusual.
