Physiological Introduction or Principles of the Human Body

suppose 1. that the internal and indeed essential principles of the entire substantial body, both "in being" and "in fact," are those from which no natural substantial bodies are made from themselves, nor from others, but from which all are made. These principles or parts of the whole, according to most Peripatetics, are further either primary (that which) or secondary (that by which).
Suppose 2. that the essential parts of the substantial whole must be of such a nature that one of them is indifferent to composing this or that whole, and thus is matter or a certain common subject or material principle, by virtue of which this substantial whole, for example, agrees with every other. The other, however, is not indifferent but actually determining matter rather to compose this, but not that, substantial whole, and thus is form or a formal principle, by virtue of which this substantial whole, for example, differs from every other. Thus, the primary parts of the whole "in being" seem to the Peripatetics to be such primary matter, form, and the privation of the former form;