De Agricultura

and of these some are simple, and others are not simple; and of those which are not simple some are conjunctive, and others are adjunctive in a greater or lesser degree; moreover some are disjunctive, and there are others which come under a similar description. Again, some are true, some are false, some are doubtful; some possible and some impossible; some are corruptible, others incorruptible; some necessary, and others not necessary; some are easy of solution, others difficult to understand; and there are other classifications akin to these. Again, of those which are imperfect there are proximate divisions into what are called categorems and accidents, and other classifications which are subordinate to these.