apologetics
Apologetics (noun) means Reasoned arguments put forward to defend a belief, idea, or set of principles.
Etymology
Comes from Late Latin apologia, from Ancient Greek ἀπολογία (apología, 'a speech in defense'), from ἀπολογοῦμαι (apologoûmai, 'I speak in one's defense'), from ἀπόλογος (apólogos, 'an account, story'), from ἀπό (apó, 'from, off') (compare apo-), combined with λόγος (lógos, 'speech') and -ics.