Enneads VI.2: The Categories of Plotinos
Neither Can Place or Time Figure Among Them
The categories of place and time are just as unable to figure among the primary genera. To be in a place, is to be in something foreign; which implies two consequences: a genus must be single, and admits of no compositeness. Place, therefore, is no primary genus. For here we are dealing only with veritable essences.
As to time, does it possess a veritable characteristic? Evidently not. If time be a measure, and not a measure pure and simple, but the measure of movement, it also is something double, and consequently composite. (This, as with place, would debar it from being ranked among the primary genera, which are simple). Besides, it is something posterior to movement; so that it could not even be ranked along with movement.