JMC : The Physical System of St. Thomas / by G.M. Cornoldi, S.J.



THE very ancient philosophers, the beginners philosophy, held that corporeal substances are nothing more than aggregations of atoms, either inert, or, at the most, endowed with attractive and repulsive force, like some sort of sympathy and antipathy. Afterwards Plato taught the doctrine of Matter and Form, infected however with grave errors, which Aristotle partly corrected, and which the Catholic Doctors, the only philosophers who had a clear and firm conception of God the Creator, afterwards rooted out.

The ancient philosophers, says St. Thomas, came to the knowledge of truth slowly and by degrees. For at first, as being less cultivated, they recognized no other beings than sensible bodies; and those among them who acknowledged movement in such, admitted that sort of movement only which takes place in some accidents, as in rarity and density, by aggregation and disgregation. Afterwards, supposing corporeal substance to be uncreated, they assigned some causes for their accidental changes, as, for instance, friendship, strife and such like. Thence they went on to distingnish substantial form and matter, which they supposed to be uncreated, and they perceived that substantial trausmutations happen in bodies."{1}

We shall proceed to enquire bow they came to this knowledge.

Plato in his Timaeus remarks that in the sensible universe every being is subject to substantial changes without a continual annihilation of previous things and continual creation of succeeding ones. Hence he inferred that in this changing of substance there always remains a substratum, or subject, -- a matter which is adapted and transformed successively into various natures. Thus fluids become plants, and plants become the flesh of brutes and even of man. And, since by such transforming of matter the eternal forms or ideas are determined, there must be in the universe a matter that is itself deprived of all determinate nature and is disposed for receiving those species which it derives from the communication or impression of the archetypal ideas. "Three things," he says, "have here to be distinguished: that which is generated (the new nature); that in which it is generated (the matter); that from which the generated thing gets its proper likeness (the idea or form). Now, if these things be compared, the nature generated resembles an offspring; the thing in which it is generated resembles a mother; and that from which it gets its likeness resembles a father. This doctrine must be understood to mean that, as the forms of things are distinguished by every sort of variety, this womb i.e. matter, thereto compared could never be well disposed for the formations to be produced in it, unless it were formless, quite void of all forms whatsoever; because, if it already had in itself any of those natures for which it is in a state of potentiality, it would not be capable of receiving a contrary form. Thus, if it were essentially water, how could it be changed into wood? It would inconceivably be at once water and wood. But, as it is potentially all these things, it cannot have the form of any, just as modelling clay has none. As the matter of scented unguents is purposely without scent, and modelling clay has no shape till the artist has modelled it, so the thing that is to be modelled according to the eternal ideas must have no form natural to itself. Therefore the mother, or receptacle of the corporeal universe, is neither earth, nor air, nor fire, nor water, nor that which constitutes their nature, nor something else composed of them, but rather it is a certain invisible. something, a formless womb, potentially everything, incomprehensibly participating in the Divine nature through the impression that it receives from the archetypal ideas. Such a womb cannot be known as it is, but only as we have explained it." In these words Plato gives us a doctrine almost perfect as to the essence of bodies; but he spoilt it by his theory of ideas subsisting outside the Divine Mind, and by his belief that the matter which receives the impression of them is eternal.

St. Augustine, who was a great admirer of Plato, vainly sought from learned men that knowledge of matter which he afterwards gained when he had considered the passing of things from one substantial form to another, and seen that all through the change between two terms there must remain in both something identical and itself indifferent to both. "O my God," he said, "if I were to speak or write what Thou hast taught me about this! When I heard of it from those who understood it not, I heard the name without knowing what it meant, and, thinking of it under innumerable forms, precisely for that reason thought not of it as it is. Ugly and horrible forms passed in disorder through my mind; but forms they were all the while. I called them formless, not as being without form, but because they were such that the sight of them was too strange and hideous for human infirmity to bear. That of which I thought was not formless by privation of all form, but only in comparison with more beautiful forms; and right reason showed me that, if I wanted to think of the formless, I must take quite away all remains whatsoever of form. But this I was unable to do; for I could think more easily that what has no form is nothing, than think of something between a thing formed of nothing, not formed and not nothing, formless and therefore near to nothing. Then, instead of continuing to imagine various changes of bodies already formed, I fixed my attention on the bodies themselves, examining more deeply their mutability, how they cease to be what they were, and begin to be what they were not; and I suspected that such passing on from form to form must be through a something without form, yet not pure nothing. But I wanted to know, not to conjecture. If I could unfold all that in this question Thou hast made clear, who among my readers would be able to understand it? But my heart will never cease to give thanks and praise for what it cannot express."{2}

That St. Thomas formed his conception of materia prima in the same way is evident in many passages. Here is one of them: "He [Aristotle] declares the aforesaid principles, and affirms that the nature firstly subject to change, i.e. materia prima, cannot itself be known, inasmuch as things are known through their form, while materia prima is the subject of every form. The thing is known by analogy, i.e. according to proportion. Thus we know that wood is something really distinct from the form of a bench or of a bed, because the wood is sometimes under the one form and sometimes under the other. When therefore we see that what was air becomes water, we must say that there is something existing beneath the forms of natural substances," (for instance, under the form of water and the form of air,) "just as in artificial ones, wood is something besides the form of a bench or the form of a bed, or copper is something besides the form of a statue. Therefore that which is to natural substances as copper is to a statue and wood is to bed, and every material and formless thing is to its form, that thing we call materia prima."{3} Materia prima is then the SUBJECT OF ALL THE SUBSTANTIAL TRANSFORMATIONS OF THE CORPOREAL UNIVERSE, which from the beginning of the world, while the various natures of things have perished and are perishing to make way for new ones, has remained and remains always the same. Yet some people believe that St. Thomas understood materia prima to mean pure nothing or the possibility of forms; and this in defiance of such passages, for instance, as the following in the Summa Theologica, P. i. Q. xiv. a. xi. ad 3, where we read Materia, licet recedat a Dei similitudine secundum suam potentialitatem, tamen, in quantum vel sic esse habet, similitudinem quamdam retinet divini esse. And in the Quaestiones Disputatae, De Verit. Q. iii. a. v. ad 1, he says: Quamvis materia prima sit informis, tamen inest in ea imitatio primae formae. Quantumcumque debile esse habeat, illud tamen est imitatio primi entis; et secundum hoc potest habere similitudinem in Deo.

The followers of the Mechanic and Dynamic systems have quite a different conception of materia prima. The former suppose it to be inert atoms, while the latter consider it as a subsisting form in the manner of mathematical points. According to these two theories the atoms and the forces would not be the subject of substance, but true substances. An atom of oxygen, for instance, which with hydrogen forms water, is not merely an atom, but has the nature of oxygen, not that of hydrogen; whereas, according to the doctrine of Plato, Aristotle, St. Augustine, St. Thomas, and so many other men of noble genius who followed them, the potential entity which was there constituted in the nature of oxygen, and which afterwards, by union with hydrogen, became water, is materia prima. It is called prima to mark it as the first requisite for bodies, in order to constitute their substantial being, which substantial being is first; and also to distinguish it from that which is called materia secunda (secondary matter), which becomes the subject of various accidental modifications. We must now speak of the form whence that primary constitution proceeds.

{1} Summa, P. i. Q. xliv. a. 2.

{2} Confess, I. xii. c. 6.

{3} In I. Phys., lect. xiii.

<< ======= >>