  But Descartes also offers a different gloss on the obscurity of sensory ideas. He allows that such ideas may be “true” in the sense of representing something positive in things, but that they may do so in such a way that “the reality which they represent is so extremely slight that I cannot even distinguish it from a non-thing” (7:44).  Accordingly, sensory ideas are not misrepresentations, they are simply so obscure and confused that we cannot tell what their representational content might be by considering their experienced character, such as the phenomenal character of cold or of color. (Metaphysics and natural philosophy are needed to tell us what our color sensations obscurely represent: properties of object-surfaces that reflect light a certain way—see Sec. 5.) In this case, “material falsity” would not amount to misrepresentation but to representation so obscure that it leaves room for mistaken judgments, such as the so-called “resemblance thesis,” that qualities in objects resemble our sensations of them. On this interpretation, Descartes is saying that the resemblance thesis arises not because the sensory ideas of cold or of color misrepresent those qualities in objects, but because we make a cognitive error, stemming from the prejudices of childhood (as mentioned in Sec. 3.1 and discussed more fully in Princ. I.66–72), in affirming the resemblance thesis.