_Note to p. 14._—Ocellus is wrong in ascribing two powers only to each of the elements, instead of three, as is clearly shown by Proclus, in the following extract from his admirable Commentary on the Timæus of Plato. “There are some physiologists (says he) who ascribe one power to each of the elements; to fire indeed heat, to air frigidity, to water moisture, and to earth dryness; in so doing, entirely wandering from the truth. In the first place, because they subvert the world and order. For it is impossible for things to be co-adapted to each other, when they possess the most contrary powers, unless they have something in common. In the next place, they make the most contrary natures allied to each other, viz. the hot to the cold, and the moist to the dry[26]. It is necessary, however, to make things which are hostile more remote than things which are less foreign. For such is the nature of contraries. In the third place, therefore, the first two powers will have no sympathy whatever with the rest, but will be divulsed[27] from each other. For it is impossible to say what is common to humidity and frigidity. And in addition to all these things, as the elements are solids, they will not be conjoined to each other by any medium. It has however been shown that it is not possible for solids to be conjoined through one medium. Nor can they be conjoined without a medium. For this is alone the province of things that are perfectly without interval. “But some others, as Ocellus, who was the precursor of Timæus, attribute two powers to each of the elements; to fire indeed heat and dryness; to air, heat and moisture; to water, moisture and coldness; and to earth, coldness and dryness. And these things are written by this man in his treatise On Nature. In what, therefore, do these err who thus speak? In the first place, indeed, wishing to discover the common powers in the elements, in order that they may preserve the co-arrangement of them with each other, they no more assign communion than separation to them, but equally honour their hostility and their harmony. What kind of world, therefore, will subsist from these; what order will there be of things which are without arrangement and most foreign, and of things which are most allied and co-arranged? For things which in an equal degree are hostile and peaceful, will in an equal mode dissolve and constitute communion. But this communion being similarly dissolved, and similarly implanted, the universe will no more exist than not exist. In the second place, they do not assign the greatest contrariety to the extremes, but to things most remote from the extremes; though we everywhere see, that of homogeneous natures, those which are most distant have the nature of contraries, and not those which are less distant. How likewise did nature arrange them, since they are most remote in their situation from each other? Was it not by perceiving their contrariety, and that the third