This short treatise is a further enquiry into the nature of sense-perception. It stresses that the soul takes an active, rather than a passive, role, in the process of perception; the imagery of ‘impressions’ upon the sense organs originating from sense-objects is therefore inappropriate, and should be abandoned. This conclusion leads in turn to a re-examination of what happens in the case of memory (a topic already addressed in 4.3–4). It is not a matter of the retention of impressions; it is rather an active power, that works on impressions received from the senses or from the intellect.
§1. The theory of sense-perceptions as ‘impressions’ does not give a correct view of the facts.
§2. This is because the soul is an active power, not a passive recipient of data in respect of any of the senses, even taste and smell. This is much clearer in respect of objects of intellection, which arise from within.
§3. Memory too is an active power. The way memory operates shows that it is not just a conservation of impressions, as indicated by the ways in which one can train it.