What shall be said of thickness and thinness, of fatness and leanness? If the element common to these conceptions be a power belonging to the capacities, dispositions, and physical powers, which gives to each object the power it possesses, the statements of the absence of power will no longer be classified along with (the powers). Besides, in what sense can we call the figure and form of each thing a "power?" Further, essence would have been deprived of all powers that were essential, retaining only those it might have received. Then, quality would comprehend all actualizations of the beings, which, properly, are actualizations only so far as they act spontaneously; and also all actualizations of these properties, but only so far as they really exist. But quality consists in (unessential) powers (such as habituations and dispositions) classified below beings.[263] For instance, boxing ability does not belong among necessary human qualifications, such as rational functions. The latter would not be called a quality (as we would speak of boxing ability); and reasoning would be considered a quality only figuratively. MERE DIFFERENTIALS OF BEINGS ARE NOT GENUINE QUALITIES. A quality is therefore a power which adds (essential) characteristics to already existing beings. These characteristics which differentiate beings can therefore be called qualities only figuratively. Qualities are, rather, actualizations and reasons, or parts of reasons, which proclaim the "whatness," though the latter seem to qualify being. As to the qualities which really deserve this name, which "qualify" things, which we generally call "potentialities," they are the reasons and shapes, either of the soul or the body, such as beauty or ugliness.[264] NOT ALL QUALITIES ARE REASONS. How can all qualities be potentialities? It is easy to see that beauty and health are qualities. But how could ugliness and sickness, weakness and general impotence, be qualities? Is it because they qualify certain things? But what hinders the qualified things from being called such by mere nomenclature, as homonyms, and not because of a single (all-sufficient) reason? Besides, what would hinder them from being considered not only according to one of the four modes,[265] but even after each one of the four, or at least after any two of them? First, the quality does not consist in "acting" and "experiencing";[266] so that it is only by placing oneself at different viewpoints that one could call what "acts" and "experiences" a quality, in the same sense as health and sickness, disposition and habitude, force and weakness. Thus power is no longer the common element in these qualities, and we shall have to seek something else possessing this characteristic, and the qualities will no longer all be reasons. How indeed could a sickness, become a habituation, or be a reason? QUALITY IS NOT A POWER BUT DISPOSITION, FORM AND CHARACTER.