It may be asked however, why, if memory be a "faculty" (a potentiality) or disposition,[234] we do not immediately remember what we have learned, and why we need some time to recall it? It is because we need to master our own faculty, and to apply it to its object. Not otherwise is it with our other faculties, which we have to fit to fulfil their functions, and though some of them may react promptly, others also may need time to gather their forces together. The same man does not always simultaneously exercise memory and judgment, because it is not the same faculty that is active in both cases. Thus there is a difference between the wrestler and the runner. Different dispositions react in each. Besides, nothing that we have said would militate against distinguishing between the man of strong and tenacious soul who would be inclined to read over what is recalled by his memory, while he who lets many things escape him would by his very weakness be disposed to experience and preserve passive affections. Again, memory must be a potentiality of the soul, inasmuch as the soul has no extension (and therefore could not be a storage-place for images which imply three dimensions). SOUL EVENTS OCCUR VERY DIFFERENTLY FROM WHAT IS SUPPOSED BY THE UNOBSERVANT OR UNREFLECTIVE. In general all the processes of the soul occur in a manner very different from that conceived by unobservant men. Psychic phenomena occur very differently from sense-phenomena, the analogy of which may lead to very serious errors. Hence the above unobservant men imagine that sensations and memories resemble characters inscribed on tablets or sheets of paper.[235] Whether they consider the soul material (as do the Stoics), or as immaterial (as do the Peripatetics), they certainly do not realize the absurd consequences which would result from the above hypothesis. SIXTH ENNEAD, BOOK ONE. Of the Ten Aristotelian and Four Stoic Categories. HISTORICAL REVIEW OF CATEGORIES.