Ideas, Pictures, and the Directness of Perception in Descartes and Locke

How are we to understand philosophical claims about sense perception being direct versus indirect? There are multiple relevant notions of perceptual directness, so I argue. Perception of external objects may be direct on some notions, while indirect on others. My interest is with the sense in which ideas count as perceptual mediators in the philosophy of Descartes and Locke. This paper has two broader aims. The first is to clarify four main notions of perceptual directness. The second is to support my contention that in the texts characterizing ideas as immediate objects of perception, Descartes and Locke are invoking the notion of directness I call 'objectual'. This notion is modeled on the way a picture mediates perception of the pictured object. The upshot of my account is that - with respect to the objectual notion of directness - Descartes and Locke each hold an indirect theory of perception.