Motion is existence after non-existence and being mixed with non-being...

Motion is existence after non-existence and being mixed with non-being, and as the law of cause and effect demands, any contingent being needs a cause in order to exist. Objection It is true that matter ( māddah ) is in constant motion and change, and motion and change, in turn, necessitate renewal ( tajaddud ) and contingency, but the same concomitance makes renewal and contingency perpetual and permanent for matter.

That is, matter’s nature of being alterable and in constant motion shall be perpetual and permanent and anything which is perpetual and permanent is not in need of any cause. Reply Motion and change are characteristics of matter, and matter is qualified ( mawṣūf ) as ‘object in motion’. As such, in relation to motion matter serves as recipient or object.

For this reason, it makes no difference whether motion can be distinguished from matter or not, and as reason dictates and experience testifies to the emergence of a phenomenon, the existence of the recipient is not sufficient because the existence of the agent is also necessary. It is thus impossible for the mover ( muḥarrak ) to be identical with the moved ( mutaḥarrik ) object.

As the law of causation dictates, therefore, motion is in need of a cause other than than its recipient matter, whether the motion is essentially inseparable to the matter or separable to it.[^5] This discourse does not also contradict the law of inertia in physics because the substance of the said law is that in preserving the motion it has, a physical body is in need of an external factor and it is in need of the external factor only in terms of changing the position or speed of the motion.

And the substance of the rational principle is that the contingency of the motion necessitates an external cause although it is possible that the said cause considers the motion essential and inseparable to the body such that for the continuity of the motion, it may not be in need of an external cause.

Given this, the incorrectness of the assumption of the perpetual and moving matter in interpreting the emergence of the phenomena in the world of nature becomes clear, because the sole perpetuity of their existence is not sufficient to explain their motion. Motion needs not only a recipient ( mutaḥarrik or the moving object) but also an agent ( mutaḥarrak or mover).