Is the power of perception common to the reasonable soul and to the
irrational soul, and will we grant that it possesses the memory of
sense-objects and of intelligible things? To recognize that it is one
and the same power which equally perceives both kinds of things, is
already to take one step towards the solution of the problem. But if we
divide this power into two, there will nevertheless still be two kinds
of memory; further, if we allow two kinds of memory to each of the two
souls (the rational and the irrational), there will be four kinds of
memory.