'aphorize' originates from Greek, specifically the verb 'aphorizein', where 'apo-' meant 'away' and 'horizein' meant 'to bound, limit, or define'.

'aphorize' was formed in English by back-formation from 'aphorism' (from Greek 'aphorismos' via Latin/Medieval Latin), ultimately from Greek 'aphorizein'; the English verb arose in the modern period (later centuries) to mean creating aphorisms.

Initially (in Greek) it carried the sense 'to separate or set off (by a boundary/definition)', but over time it evolved into the modern English sense 'to express briefly or in the form of an aphorism'.