Found something! Here's my summary..

Since Aesthetics is all about one’s perceptions based on their experiences, this clearly links to one’s judgments after perception. Aesthetics is able to be split into concepts which are open and closed. A closed concept would be that of which has rules and conditions for example; a bachelor – it is necessary to be male and unmarried, though of marriageable age, and together these three conditions are sufficient. However, for the open concept of Aesthetics, it is difficult to define a definition because there are no sufficient conditions for application. Frank Sibley, a British philosopher concentrating in the field of Aesthetics has said that the concepts of Aesthetics are not rule or condition-governed, but requires a heightened form of perception such as taste, sensitivity or judgment to be able to experience it. Sooo.. if there aren't any sufficient conditions for application how are we able to make legitimate Aesthetic judgments?  Sibley has mentioned that if the concepts were not perceived by the human senses then the judgments were most likely metaphoric, comparing them to other subjects or that of human characteristics.