in Logic and Rhetoric, an argument consisting only of two propositions, an antecedent, and a consequent deduced from it. The word is Greek, ἐνθυμημα, formed of the verb ἐνθυμεῖσθαι, "to think, conceive," a compound of εν and θυμος, "mind."

The enthymeme is the most simple and elegant of all argumentations; being what a man, in arguing closely, commonly makes, without attending at all to the form. Thus, that verse remaining of Ovid's tragedy, entitled Medea, contains an enthymeme; Servare potuit, perdere non posse rogas: "I was able to save you; consequently to have destroyed you." All the beauty would have been lost, had all the propositions been expressed; the mind is displeased with a rehearsal of what is nowise necessary.

Sometimes, also, the two propositions of an enthymeme are both included in a single proposition, which Aristotle calls an enthymematical sentence, and gives this instance thereof: Mortal, do not bear an immortal hatred. The whole enthymeme would be, Thou art mortal, let not, therefore, thy hatred be immortal.