rătĭōnāle, is, n., the oracular breastplate of the Jewish highpriest, Vulg. Exod. 25, 7; id. Lev. 8, 8; also called rationale judicii (transl. of LXX. τὸ λογεῖον τῆς κρίσεως ), id. Exod. 28, 15.
Of or belonging to reason, reasonable, rational, endowed with reason: falsa est (finitio), si dicas, Equus est animal rationale: nam est equus animal, sed irrationale, Quint. 7, 3, 24: homo est animal rationale, id. 5, 10, 56; cf. id. 5, 8, 7; and: nec si mutis finis voluptas, rationalibus quoque: quin immo ex contrario, quia mutis, ideo non rationalibus, id. 5, 11, 35; so without a subst.: a rationali ad rationale (translatio), id. 8, 6, 13.
Reasonable, depending on reason: in causā rationali, Auct. Her. 2, 12, 18: philosophia, i. e. logic, Sen. Ep. 89, 17; also called rationalis pars philosophiae, Quint. 12, 2, 10: disciplina, i. e. theoretical science (opp. to usus and experimenta), Cels. praef.; also ars, id. ib.; hence, rationalis medicina, theoretical therapeutics; and rationales medici, medical theorists, id. ib.
In rhet., i. q. ratiocinativus, of or belonging to a syllogism, syllogistic: genus (quaestionum), Quint. 3, 5, 4; 6, 54; 78; 86; cf. status, id. 3, 6, 56; 66.
Hence, adv.: rătĭōnālĭter, in a reasonable manner, reasonably, rationally, Sen. Ep. 109; Tert. Anim. 16 al.