Article 28

In the twenty-eighth article, the question is raised whether something is said to enter into the composition of another in two ways: in one way, by its own essence by way of a material and formal principle (and thus in no way does something of the nature of a heavenly body enter into the composition of a human body or of other mixed bodies); in the second way, something enters into composition of another by an effect of its power (and in this way the nature of a heavenly body enters into the composition of a human body and of all mixed bodies).

This is necessarily true since heavenly bodies are the cause of generation and corruption in these inferior things, as Dionysius says.