To avoid the difficulties inherent in this theory, the Schoolmen were led to adopt infinite divisions among the substantial forms. In this way the Jesuits of Coïmbre admitted three kinds of these forms: first, the being which does not receive its existence from a superior being and is not received into an inferior subject,—this being is God; second, the forces which receive their being from elsewhere without being themselves received into matter,—these are the forms which are entirely free from any corporeal concretion; third, the forms dependent in every respect, which obtain their being from a superior cause and are received into a subject,—these are the accidents and the substantial forms which determine matter.
Other Schoolmen adopted divisions still more minute and distinguished six classes of substantial forms, as follows: first, the forms of primary matter or of the elements; second, those of inferior compounds, like stones; third, those of higher compounds, like drugs; fourth those of living beings, like plants; fifth, those of sensible beings, like animals; sixth, above all the rest, the reasoning (rationalis) substantial form which is like the others in so far as it is the form of a body but which does not derive from the body its special function of thinking.
Some have thought, perhaps, that Molière, Nicole, Malebranche and all those who in the seventeenth century ridiculed the substantial forms, calumniated the Peripatetic Schoolmen and gratuitously imputed absurdities to them. But they should read the following explanation, given by Toletus, of the production of fire: "The substantial form of fire," says Toletus, "is an active principle by which fire with heat for an instrument produces fire." Is not this explanation even more absurd than the virtus dormitiva? The author goes on to raise an objection, that fire does not always come from fire. To explain this he proceeds, "I reply that there is the greatest difference between the accidental and the substantial forms. The accidental forms have not only a repugnance but a definite repugnance, as between white and black, while between substantial forms there is a certain repugnance but it is not definite, because the substantial form repels equally all things. Therefore it follows that white which is an accidental form results only from white and not from black, while fire can result from all the substantial forms capable of producing it in air, in water or in any other thing."
