IMAGINATION Copy link • IMAGINATIONcogitatio; but the post-classical imaginatio (Plin., Tac.) or vis imaginandi may be necessary in a philosophical treatise; Krebs, Weber, Uebungsch., p. 264. A mere imagination, species inanis: a creature of the imagination, species or forma menti objecta. To exist in imagination only, in opinione esse (opinatus in past participle is classical). Contrivance, device, Vid.