Knowledge of Angels is a philosophical story by Jill Paton Walsh set in a fictional country, Grandinsula, based on Mallorca, following an atheist named Palinor and a girl raised by wolves named Amara, and documenting their actions and responses to being thrust into a medieval Christian society.

The first main character, Palinor, is found washed up on a beach, near dead and with no forms of identification or proof that he is who he says he is-an elected Prince of a foreign land. No-one from Grandinsula has heard of this country, and it is soon learned he does not believe in God, an offense punishable by death. It falls to the Cardinal Prince of Grandinsula to convince Palinor to convert, and he delegates this task to the loyal Church scholar Beneditx. Beneditx has many theological conversations with Palinor, yet fails to convince him to convert (and, in fact, ends up suffering from a CrisisOfFaith himself).

The other side of the story, with Amara, focuses on how a group of nuns hope to raise her to become 'human', and yet keep her ignorant of God, so as to see whether knowledge of God is innate or learned- a plan orchestrated by Severo, as, if it can be proved that humans are not born with knowledge of God, then Palinor will not be held guilty of rejecting God- rejection can be punished, ignorance cannot be. However, though early tests with Amara would suggest knowledge is learned, she is later couched by the nun caring for her in proclaiming belief in God, so she will be let go rather than kept confined waiting to see if she finds it by herself. Thus it is left unclear as to whether this knowledge really is innate or not, although Amara shows no signs of it before this.

Either way, the Church authority uses this as proof of Palinor's sin, and puts him to death for heresy.

It's on the A level syllabus.

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!Contains examples of the following tropes:

* ArtisticLicenseReligion: Catholic doctrine did not view witchcraft as heresy in 1450. In fact, the official take was that witchcraft claims were delusions or lies, with it being sinful to believe they were true. Thus an Inquisitor would not tell people that witchcraft was a sign of heresy. Atheism is also not heresy, and so the Inquisitor would have no authority over Palinor. The only problem would be him trying to convince anyone else of atheism, which he didn't do.
* AsTheGoodBookSays: Used by the religious side of the main debates between Beneditx and Palinor, along with 'As [[WordOfDante Thomas Aquinas]] Says'.
* AuthorTract: The entire book is one of these about theism and atheism, set as a story.
* ChurchMilitant: The Holy Inquisition, naturally.
* CoitusEnsues: About two-thirds of the way through the book, Palinor has a [[ThreeWaySex threesome]] with his (female [[BiTheWay and]] male) servants, which comes up quite unexpectedly while adding nothing to the plot. It also paints him in a somewhat bad light, given the {{questionable consent}} on their part as they're dependent on him for livelihood and used to obeying his orders.
* CrisisOfFaith: Beneditx has one after talking with Palinor, and becoming convinced by Palinor's atheist retorts.
* DeliberateValuesDissonance: The values of Renaissance Christians are ably demonstrated for the reader, such as the far more powerful role of religion in people's lives-to the point of harsh persecution toward dissidents. Additionally, the Christian characters find Palinor's view hard to fathom (as indeed real Christians would have at the time). The Inquisitor finds the idea of religious tolerance, as Palinor describes in his homeland, utterly appalling.
* DownerEnding: Palinor is killed, Amara has gone off to live a life of isolation, and an Aclaran fleet is coming to punish the island for Palinor's death.
* EasyEvangelism: {{Averted}} by how set Palinor is in his beliefs (or lack thereof), making Beneditx's job of converting him impossible. Palinor outright states he cannot be convinced.
* ElectiveMonarchy: Palinor is an elected prince of his home country, Aclar.
* HeelFaithTurn: Beneditx was hoping to cause one in Palinor, though Palinor wasn't a Heel to begin with (the Church saw Palinor as evil for rejecting God, and so Beneditx was hoping that, by converting Palinor, the Church would see him as good and spare him).
* HollywoodAtheist: {{Discussed}}. Palinor does not fit the stereotypes, surprising the Christian characters, who believe an atheist has no reason to be moral.
* KarmaHoudini: Although the abbess curses them, she doesn't inform the authorities of the shepherds raping Amara, and they're never punished or even arrested.
* KillItWithFire: At the close of the book, Palinor is burned at the stake by the Inquisition for heresy.
* MercyKill: Palinor is killed with a material that emits deadly yet painless fumes to spare him from being burned alive.
* MyGodWhatHaveIDone: Severo reacts this way after he realizes what is going to happen with Palinor after he turned him over to the Inquisition.
* ReligionIsRight: Beneditx thinks his arguments (starting with Aquinas' 5 Ways) prove God exists.
* ReligionIsWrong: He becomes convinced that they don't after hearing Palinor's replies, which, to him, means that there is no evidence for a God, and so how could one exist?
* StaticCharacter: Palinor is a big example of this, made more prominent by how much he changes those around him (for example, Palinor's beliefs are the same on the first and the last page, while Beneditx has had a CrisisOfFaith through merely talking with him).
* TheSoulsaver: Beneditx (and Severo) try to be this for Palinor.
* UnwittingPawn: Amara is one in Severo's plan to see if knowledge of God is innate or learned, and while Severo is not the villain, the plan ends up causing Palinor to be executed.
* WillNotTellALie: Palinor refuses to lie, even when his life is on the line, saying it would demean him.
* WildChild: Amara, raised by wolves from a young age, is one (and is actually based off of a real life feral child found in France).