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



IN creating actuated matter by substantial forms God produced also what may be called the seminal causes of things, which enable substances to produce others like or unlike themselves. Strictly speaking, however, this term expresses the virtue communicated by God to a living substance, and through it to its seed, by which it generates another substance of the same species. Furthermore it expresses the virtue by which even things without life are the causes of substantial change. "From that which is more perfect," says St. Thomas, "the denominations of things are taken. Now the most perfect of all corporeal substances are living substances. . . . But evidently the seeds from which they are generated are their active and passive principle; and therefore all the active and passive virtues that are principles of generation and of natural changes are suitably called by St. Augustine [3 De Trinitate ] seminales rationes. The active and passive virtues may be considered in a manifold order. Firstly, as St. Augustine says,{1} they are principally and originally in the very Word of God, as ideal essences. Secondly, they are in the elements of the world, where from the beginning they were produced at once, as universal causes. In a third way they are found in those things that out of universal causes are in course of time produced, for instance, in this plant or that animal, as in particular causes. In a fourth way they are in the seeds produced by animals and plants.{2} . . . Without these seminal virtues, given by God, the living things first created would have disappeared from the earth, and that continual transformation of substances, which is so necessary for the maintenance of such, would have ceased.

This most wise providence of the Creator is thus described by St. Thomas: "The coming forth of creatures from God is like the coming forth of artistic works from an artist; and therefore, as artificial forms in matter proceed from the artificer, so do natural forms and virtues descend from the ideas in the Divine Mind. . . But the works of God differ in two respects from those of the artificer. Firstly, on the part of the matter; for the artificer does not produce that, but works on it, and never could give to it the power of receiving those forms which he communicates thereto; but God, Who is the cause of all being, not only gave to things their forms and natural being, but also communicated to matter (materia prima) the power of receiving whatever He may please to operate in it. Secondly, on the part of the forms; for the forms introduced by the artificer are not able to produce a being like themselves. A wooden bed cannot bring forth another wooden bed, though, if reduced to ashes, it may help to form a plant; but the natural forms can produce the same things, and therefore have the property of seed, in virtue of which they may be called seminal."{3}

Having thus given a general sketch of the Physical System as to the generation of things, we must now descend to the particular, and apply it to the various kinds of corporeal substances. Some living things have only vegetative life, and others have sensitive life also. The former are called plants, the latter animals. God gave to the primitive animals the above mentioned seminal virtue, but so that in the one sex it should be an active principle, in the other passive, and that the seminal substance communicated by the genitors should have life, not actually, but virtually, as having the power to produce, under requisite circumstances, a living thing. In such generation therefore there is no creation, properly so called; for the anima sensitiva is caused by the originating seminal virtue, which, though simple in itself, is yet material, as being so tied to matter that it can neither operate nor exist separate therefrom. Of course we are prescinding from man, because the human soul is immaterial, and therefore, even when separated, can exist and operate.

God has not given to corporeal substances," says St. Thomas, "by means of the seminal virtues, the means of producing a human soul; but He has given to brutes the power of so producing the anima sensitiva. And this," he adds, "the Sacred Scripture seems to indicate in the book of Genesis. There, speaking of the origin of other animals, it ascribes their souls to other causes, saying Producant aquae reptile animw viventis, &c.{4} But, when speaking of man, it shows that his soul was immediately created by God; for it says that God formed man of the slime of the earth, and breathed into his face the breath of life."{5} And here we must remark that the conjunction of the two seminal principles in every living thing is called conception, and is prior in time to the production and existence of the vital principle or soul, which' is called animation. It is absurd and against facts to suppose that, the conception and the animation are simultaneous.

The same thing is to be said of plants; for God conferred on them similar virtues, and they confer those virtues on the seminal substances, so that the one gives the active, and the other the passive seminal principle, which, being conjoined, give the completed seed, not living actually, but having efficient power of life. When there is no distinction of sex one part of the same plant gives the active principle, and the other the passive. "Those animals," St. Thomas says, "that have perfect life have also a perfect generation, and therefore are distinguished as active and passive. But it is not so in the imperfect life that plants have; for in the same plant there is the twofold virtue, active and passive, though sometimes the active is found in one, and the passive in another, so that the one plant is said to be masculine and the other feminine."

Clearly then the distinction of sex in plants is not a recent discovery of modern science, as some people would have it to be. Here we must remark, by the way, that, if any human being could by chemical art determine with certainty the elements of which the seminal substance of living beings is composed, and combine them so as to make of it a substance quite similar materially to the completed seed, the substance would nevertheless have no seminal virtue, because it would not proceed from living parents. And therefore if, per impossibile, it were possible for any man to produce by art the organism of a plant or of a brute, he could never produce a live brute or a live plant.

The two principles of seminal virtue for the generation of animals and plants may, by analogy, be said to be required for the production of a new substance in beings without life. Oxygen and hydrogen will not produce water, although put together in the right proportions, unless there is some extrinsic cause to modify their virtue, so that their mutual action may produce a change of one relative principle into another, thereby constituting the nature of water. Evidently these elementary substances are different from non-elementary or mixed substances. The elementary substances do not result from the union of two other substances; but by physically uniting they produce a new substance in a different nature, viz, mixed substances. But why do we call these mixed, when in natural sciences now they are called composite, and the word mixed is used to signify a mixture? The reason is, that since every corporeal substance is composed of matter and form, the name of composite belongs as much to the elementary as to the non-elementary; so that a mixed substance cannot properly be called a mixture, but only two or more substances locally mingled by aggregation, each keeping its primary nature. The word mixed belongs of right to that oniy which is produced by physical union, so that from two or more substances there results one substance only.

And, since anything may be resolved into the elements of which it is constituted, any mixed substance (say water) may be resolved into its component parts.. Aristotle, explaining as a philosopher the inmost nature of elements, tells us{7} that an element of bodies is that substance which is obtained by resolution of others, and which cannot be resolved into another of a different species. St. Thomas, commenting on him, says: "An element of other bodies is that into which those other bodies are decomposed or resolved; for not every cause may be called an element, but oniy that whicli enters into the composition of a thing."{8} Again he says: " In natural corporeal substances, those into which all mixed bodies resolve themselves are called elements of bodies; and consequently they are those from which the mixed bodies result. And the bodies called elements are not divided into others differing from each other in species, but into similar parts." {9} Hence he calls elementary bodies "simple." "Elementary bodies," lie says "are simple, and there is no composition in them except that of matter and form." {10} Following this doctrine, Toledo says: "In two ways we may conclude that elementary substances are. Firstly, from the dissolution of bodies; it being a fact that some decompose into bodies of a different nature, and others into bodies of the same nature. The resolved parts are evidently composed of those into which they do resolve; and an infinite process of resolving is repugnant to reason. Therefore, there must be bodies tliat are not resolved into others, or, in other words, elementary bodies. Secondly, we may conclude this likewise from composition. For we know that many bodies are made by mixture (now called chemical combination) ; but elementary bodies cannot be so made. Therefore those really are simple bodies, which do not result from composition of others." 1:

Such is the doctrine professed in the system before us ; but it does not claim to determine how many and which the elementary bodies are. These have been supposed to be four, and thought to be twenty or fifty, and now the amount is over eighty; nor can any one say how many they may be found to be. By means of reasoning we can only affirm with Toledo that "the elements are more than one."{11} That much we can affirm; for otherwise the production of new natures would be impossible, because the union of two equal things cannot constitute something of a different species. The atomic theory, therefore, cannot be true; because, according to that doctrine, the atoms are all of the same nature. Experiment, not reason, determines which and how many elementary substances cooperate in forming this or that mixed body; and even experiment does not, after so many centuries, give with certainty a final settlement of that question.

In defending the old teachers from unjust attacks, men of high ability and great learning, such as the distinguished philosopher, Cardinal Battaglini, and the famous Professor Lorenzelli, have in their philosophical courses given another meaning to the word "elements;" but we prefer to avoid troublesome and unnecessary disputation. We simply say that since the old teachers, when teaching as philosophers, tell us that elements or elementary bodies are those bodies of which mixed bodies are composed, and which result from the decomposition of the latter, we have a right to use the same correct definition in experimental physics, for the purpose of seeing what bodies are such -- whether solid, liquid, fluid, or aerial. Modern chemists cannot deny that; for with them the element is the first in chemical synthesis and the last in chemical analysis.

{1} 6 De Gen., ad litt.

{2} Summa, P. i. Q. cxv. a. 2.

{3} In II. Sent., Dist. xviii. 1, 2.

{4} Gen., i. 20.

{5} Met., vii.

{6} Comm. in III. Sent., Dist. iii. Q. ii. a. L

{7} iii. De Caelo et Mundo.

{8} Lect. viii.

{9} In V. Met., 3.

{10} Contra Gent., iii. 23. Lib. ii. De Generat. et corrupt., Q. 4.

{11} Ibid. iii.

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