* AluminumChristmasTrees:
** Ambitious young men become monks and priests for the same reason that today they become doctors and lawyers; they do not care much about serving God, but they do want to get ahead in life and get noticed by the wealthy and powerful.
** ''Monk's Hood'' and ''Brother Cadfael's Penance'' both spotlight that the law of Wales (before its integration into what would become the United Kingdom) allowed illegitimate children to inherit their parents' property, with the same rights as those born in wedlock.
* SugarWiki/FunnyMoments: Brother Oswin being repeatedly described as a PersonOfMassDestruction. It's not that he deliberately breaks things, he's just that clumsy, and he ''tries''. Even his NeverMyFault attitude isn't malicious.
* FridgeLogic: In ''One Corpse Too Many'', the monks of Shrewsbury offer to oversee the identification and burial of the 94 men hanged after King Stephen's forces capture the castle. Fair enough, the number of executions is historically accurate. Except... shouldn't there ''also'' have been some of [=FitzAlan=]'s men who died ''during the battle'', who would also require burial? Presumably the entire garrison wouldn't have surrendered without a fight. So, there should have been quite a few battle casualties that Cadfael and his brethren would've needed to lay out for the townsfolk to inspect and locate their fallen kin, ''besides'' the ones who were captured and hanged.
* GeniusBonus: Cadfael's conflicts with Prior Robert and others are a microcosm of the intellectual conflict then raging in Western Europe between neo-Aristotelianism and Augustinianism. Neo-Aristotelianism originated in the Middle East, where Cadfael spent his youth.
* SugarWiki/HeartwarmingMoments: In the final book, when Cadfael and Olivier are finally together and the Big Secret out: Cadfael helps [[spoiler:his son]] to arm himself...
-->[...] and for a moment he had the world in his arms.
* MoralEventHorizon:
** [[spoiler:Corbière]] in ''Saint Peter's Fair'' crosses it when he implies that he'll rape Emma--or at least molest her--if she doesn't give up the MacGuffin.
** This is how Hugh Beringar, a loyal official to King Stephen, views [[spoiler:Bourchier, alias Cuthred]] betraying his liege in her darkest hour.
* TearJerker:
** In ''The Leper of St. Giles'', the old man Lazarus chooses to go quietly on his way after giving aid to, and setting matters right for, Iveta de Massard and Joscelin Lucy. He doesn't even linger long enough for them to thank him. Only Cadfael knows the truth--that he is [[spoiler:Guimar de Massard, Iveta's grandfather, reported as having died of battle wounds in the Holy Land. He is no longer actively afflicted with leprosy and is no danger to anyone, but the illness has left him grotesquely disfigured, and he is content to remain dead in the eyes of the world now that he knows his granddaughter will be safe and happy]].
** Aldwin in ''The Heretic's Apprentice'' is an old man with a colossal inferiority complex he'd been carrying his entire life, terrified of being kicked out of his job as a clerk for a wool merchant and left to fend for himself. So when Elave, a young man far more skilled than he is, returns to the family, Aldwin thinks his position is in danger and denounces him as a heretic after a drunken discussion on God and church doctrine. When he's informed Elave had no intention of taking Aldwin's place nor the family of replacing him, [[MyGodWhatHaveIDone Aldwin is devastated]] and tries to make amends, but is murdered before that can happen. And worse, [[spoiler:he died for no reason]]: the murderer thought Aldwin had [[spoiler:seen a rare book inside a box]] and silenced him, when in fact he'd been interrupted before seeing anything.

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