Abstract
In his theory of perception Aristotle is committed to the principle that there is a one-to-one correspondence between a sensible quality, the modification of a sense organ by that quality, and the content of the perceptual experience of it. But on the basis of this principle, simultaneous perceptions of different sensible qualities give rise only to distinct perceptual contents. This generates the problem of how we become aware of complex perceptual content, e.g. in discerning red from cold. This paper examines the alternative (although not equally explanatorily powerful) models that Aristotle offers in the De Anima and in his biological works to account for complex perceptual content.