An apologia (Latin for apology, from ‹See Tfd›Greek: ἀπολογία, lit. 'speaking in defense') is a formal defense of an opinion, position or action. The term's current use, often in the context of religion, theology and philosophy, derives from Justin Martyr's First Apology (AD 155–157) and was later employed by John Henry Newman's Apologia Pro Vita Sua (English: A Defense of One's Own Life) of 1864, which presented a formal defense of the history of his Christian life, leading to his acceptance by the Catholic Church in 1845.
https://en.wikipedia.org/wiki/Apologia