  As we have often in this entry, we begin with historical context since Reid's theory of the relation between sensations and qualities will appear stranger than it is without background. According to the Way of Ideas, ideas and images are mental representations in an individual's mind, and my perceptual awareness of a table depends upon my prior awareness of these ideas of sensation. This veil of perception is why advocates of the Way of Ideas struggled to provide epistemic justification for beliefs about external, mind-independent, qualities of physical objects, and avoid skepticism. But besides the epistemic problem, advocates of ideas faced a difficulty accounting for the origins of the contents of our very ideas of external objects. Though not easy to appreciate, this problem it is quite important.