To confirm something is to make it firm — not metaphorically, but literally, at least in the word's Latin origins. Confirmare was built from com- (an intensifying prefix, 'thoroughly') and firmare ('to make firm'), from firmus ('strong, stable'). The image is of something shaky being made solid, a tentative belief being pressed into certainty. English borrowed the word through Old French in the 13th century, and it quickly found two domains. In law and governance, to confirm meant to ratify officially — a king confirmed a charter, making it unshakeable. In religion, the sacrament of confirmation strengthened a baptised Christian's faith, making their commitment firm. Both senses survive. Today we confirm flight bookings, email addresses, and medical diagnoses, each time performing the same ancient act: turning something provisional into something fixed. The root firmus produced a large family in English — firm, affirm, infirm, firmament (the 'fixed' sky), and even firmware, computing's term for software that is permanently firm inside its hardware.