Abstract: This essay presents Quintilian as representative of the ancient categories of thought, in contrast to the medieval-modem one which emerged in the generations of Anselm and Abelard. Quintilian works in the first place with an exhaustive dualism of words and res: res span both what is outside the mind and what is taken into the mind, so that for him there is no medieval-modern trichotomy of words, meanings, and things. In the second place, for Quintilian the primary function of the mind is to take the outside world into itself, while in the medieval-modern context the primary function of mind is to make up meanings by which to think about things outside the mind.