Finding the condition of that body which is not receptive to change (taghayyūr). generation (kaun), and corruption (fasād), and of that body receptive to change, generation, and corruption 1

That body whose form (Ȧūrd) cannot be separated (Judā) from substratum-matter (mādda) is not receptive to generation and corruption, whereas that body whose form can be separated from its matter is receptive to generation and to corruption. Since the matter of a body cannot be without form, once matter is separated (judā) from one form, it becomes the material constituent of an entity due to another form. Consequently, for such a body X there must be a body Y with a nature (ṭab‘) opposed to the nature of X. Since its place will not remain fixed as its nature changes, both bodies must be receptive to straight motion (Junbish-i rāst). Henceforth, when the nature of the first body changes, its place cannot remain the same. Hence, it seeks another place by nature. That body in whose nature there is no straight motion is therefore receptive neither to generation nor to corruption. ² But if a body is receptive to generation and to corruption, it has no choice but to be receptive to straight motion and to seek direction (Jihat justī). In order that these bodies receptive to generation and corruption may have a direction, they must be contained within (andar īn) the realm of a body which is receptive neither to generation nor to corruption. Two distinct places cannot be sought by each body, for otherwise the distance between the directions of the two exterior bodies would be limited by the distance which created the two directions, one direction being towards one body and the other towards the other body. We have asserted, however that this cannot be the case. For these reasons, external to a body seeking direction there cannot be another body seeking direction. All other bodies are, therefore, subordinate to (andar wai) it. Thus, all bodies capable of being generated and corrupted are also combined in it as they must be. Even if there were a body receptive neither to generation nor to corruption, it would also have to be subordinate to it. All bodies must, therefore, be a unity. We shall discuss this topic more extensively in our treatise on natural science. In this manner it has become known that the substratum-matter of bodies receptive to generation and to corruption is common (mushtarak) and that it is not peculiar to (khāȦȦa) a single body.