11. If this be so, why should we recognize several kinds of qualities? Why should we distinguish capacity and disposition? Whether quality be durable or not, it is always the same; for any kind of a disposition is sufficient to constitute a quality; permanence, however, is only an accident, unless it should be held that simple dispositions are imperfect forms, and that capacities are perfect forms. But if these forms be imperfect, they are not qualities; if they be already qualities, permanence is but an accident. PHYSICAL POWERS DO NOT FORM A SECONDARY KIND OF QUALITY. How can physical powers form a secondary kind of qualities? If they be qualities only so far as they are powers, this definition would not suit all qualities, as has been said above. If boxing ability be a quality as far as it is a disposition, it is useless to attribute to it a power, since power is implied in habituation. Further, how should we distinguish the natural boxing ability from that which is scientifically acquired? If both be qualities, they do not imply any difference so far as one is natural, and the other acquired; that is merely an accident, since the capacity of boxing is the same form in both cases. THE DERIVATION OF QUALITIES FROM AFFECTION IS OF NO IMPORTANCE. What does it matter that certain qualities are derived from an affection, and that others are not derived therefrom? The origin of qualities contributes nothing to their distinction or difference. If certain qualities be derived from an affection, and if others do not derive therefrom, how could they be classified as one kind? If it be said that some imply "experiencing" while others imply "action," they can both be called qualities merely by similarity of appellation (homonymy). SHAPE IS NOT A QUALITY; BUT SPECIFIC APPEARANCE, OR REASON. What could be said of the shape of every thing? If we speak of the shape as far as something has a specific form, that has no regard to quality; if it be spoken of in respect to beauty or ugliness, together with the form of the subject, we there have a reason. ARISTOTLE WAS WRONG IN CALLING "ROUGH," "UNITED," "RARE," AND "DENSE" QUALITIES. As to rough, united, rare and dense[269] these could not be called qualities; for they do not consist only in a relative separation or reapproximation of the parts of a body, and do not proceed everywhere from the inequality or equality of position; if they did, they might be regarded as qualities. Lightness and weight, also, could be correctly classified, if carefully studied. In any case, lightness is only a verbal similarity (a "homonym") unless it be understood to mean diminution of weight. In this same class might also be found leanness and slimness, which form a class different from the four preceding ideas. PSYCHOLOGICAL THEORY OF QUALITY.