from both sense-perception and imagination because the senses can never lie and imagination is a power to make something sensed appear again, while thinking can sometimes be false. And since the mind is able to think when it wishes, it must be divided into two faculties: One which contains all the mind's ideas which are able to be considered, and another which brings them into action, i.e. to be actually thinking about them.

These are called the possible and agent intellect. The possible intellect is an "unscribed tablet"