The source tests possibility, existence, substantiality, and corporeality as candidates and argues that none alone suffices for origination. It retains composition as the proposed shared feature.
Some of its supporting cases presuppose historical metaphysical doctrines, including claims about immaterial substances and celestial bodies. They illustrate a classical philosophical argument, not independently verified modern scientific facts.
The general methodological lesson is that each causal candidate needs its own assessment, and the remaining candidate is well supported only if plausible alternatives were adequately ruled out.