Aesthetics has often been described as the philosophical study of beauty and "ugliness." It is important at the outset to see what is involved in this familiar definition, for it embodies a view of ugliness and of its role within aesthetic theory that has been the major source of contention in historical debates on the concept. The first thing to note about this view is that it takes ugliness to be a category that properly falls within aesthetic theory. Ugliness designates aesthetic disvalue as beauty designates positive aesthetic value. The two therefore constitute a value polarity analogous to right and wrong in ethics or to truth and falsehood in epistemology. Just as the field of ethics comprises responsible human actions of which some are evil and blameworthy, so, among perceptual objects, there are some that have negative aesthetic value. This does not mean that such objects simply lack...