Chapter 1 — On the opinions of the early philosophers and of Plato

The first of those who philosophized on the natures of things believed that only bodies existed and held that the first principles of things were certain corporeal elements, either one or several. (Aristotle, Metaphysics, 1, 3–4 (983b 6–985b 22); 11, 5 (1002a 8); Physics, IV, 6 (213a 29); St. Augustine, De Civitate Dei, VIII, 2 (PL 41, 225). For St. Thomas’ use of these texts: ST, I, 44, 2 (BW, I, 428–429); De Spiritualibus Creaturis, a. 10 ad 8, ed. L. Keeler, 131–133 (OSC, 121–122); Q. D. De Potentia III, 5; A. C. Pegis, A Note on St. Thomas’ Summa Theologica, 1, 44, 1–2 in Mediaeval Studies, VIII, 1946, 159–168.) And if they held the first principle to be one, either they thought it was water, as Thales of Miletus did, or air as Diogenes, or fire [as Hippasus, or vapor] as Heraclitus. (Palaeographically, there is little justification for this particular reading which we have adopted, since all 12 mss. seem to be representative of a tradition which attributes “vapor” to Heraclitus. Manuscripts “A” and “B,” i.e., CAMBRIDGE, Corpus Christi, Libr. ms. 35 and TOLEDO, Bibl. del Cabildo, 19–15 do omit Hippasus but still attribute both fire and “vapor” to Heraclitus. Manuscript “D,” i.e., VENICE, S. Marco 31, IV suppresses the phrase “ut Hippasus aut vaporem ut” and substitutes for it “ac” leaving, at the same time, a space between “ac” and “Heraclitus.” The scribe of “D” evidently deleted the troublesome phrase and left a space for a future correction. Since no sources of Greek philosophy credit Heraclitus with “vapor,” the phrase “ut Hippasus aut vaporem” seems to be an interpolation which, most interestingly, is not found in the 1488 Soncinas nor in the 1490 and 1498 Pizzamanus printed editions. Hence, we have made an emendation by suppressing the obvious interpolation and the text reads: “Et si unum, aut aquam ut Thales Milesius, aut aërem ut Diogenes, aut ignem ut Heraclitus.” For the relative value of incunabula in the establishment of a critical text, cf. above, Introduction, 13, 14 and F. Lescoe, Sancti: Thomae Aquinatis Tractatus de substantiis separatis, Introduction: Literary Problems.) If they thought the principles to be several, they thought them to be either finite in number, as did Empedocles, who posited four elements and along with them two moving principles, namely, love and strife; (Aristotle, Physics, 1, 5 (188b 34).) or infinite in number, as in the case of Democritus and Anaxagoras, both of whom posited an infinite number of minimal parts as the principles of all things, except that Democritus held that these parts were similar in kind, differing only in figure, order, and position. (Aristotle, Metaphysics I, 4 (985b 3–20); Lucretius, De Rerum Natura, I, 421 ff. (Stoic and Epicurean Philosophers, ed. W. Oates, 76 ff.); cf. K. Freeman, Ancilla to the Pre-Socratic Philosophers, 91–120; The Pre-Socratic Philosophers, 289–326.)

Anaxagoras, on the other hand, thought that in the case of diverse things which have similar parts, the first principles are the infinite minimal parts. Moreover, since all of these philosophers had the natural conviction that they should consider as god that which was the first principle of things, just as each of them had attributed to a certain corporeal element the rank of a first principle, so he likewise felt that the name and honor of divinity should be given to this element.

These things were said for this reason, that for all of these men and their followers, it was the case that no incorporeal substances, which we call angels, existed. The Epicureans, however, who traced their origin to the teachings of Democritus, posited certain corporeal gods, resembling human beings in appearance, (St. Thomas, De Spiritualibus Creaturis, a. 5, ed. L. Keeler, 65 (OSC, 67) calls them “anthropomorphitae”; cf. St. Augustine, Epist. 148, IV (PL 33, 628).) whom they held completely free and without any cares, so that by enjoying ceaseless pleasures, they would be blessed. This teaching had such a far-reaching effect that it influenced even Jewish worshipers of God, a sect of whom, the Sadducees, held that neither angels nor spirits existed. (Acts 23:8; cf. St. Thomas, ST, I, 50, 1 (BW, 1, 480).)

The early philosophers, however, opposed this opinion in three ways. For although at first Anaxagoras posited certain material or corporeal principles with the other natural philosophers, nevertheless, he was the first among the philosophers to assert a certain incorporeal principle, namely, an intellect. (Aristotle, Metaphysics, 1, 3 (984a 15–22); 1, 8 (989a 30–989b 21); Physics, VIII, I (250b 24); Plato, Phaedo, 97A.) Since indeed, according to his view, all corporeal things were mixed in all things, it did not seem possible that corporeal bodies could have been distinguished from one another unless there existed some principle of distinction which was itself completely unmixed and had nothing in common with corporeal nature.

But, although Anaxagoras’ opinion was much closer to the truth than that of the philosophers who posited only a corporeal nature, yet it falls short of the truth in two respects. First, because it is apparent from his position that he posited only one separate intellect which had produced this world by distinguishing what was mixed. But since we attribute the establishment of the world to God, from this point of view, we can gather nothing from his opinion as to the incorporeal substances which we call angels, which are below God and above corporeal natures. Second, because concerning the intellect, which he said to be one and unmixed, he seems to have failed in this respect, since he did not sufficiently express its power and eminence. Instead of defining this intellect, which he considered to be separate, as the universal principle of being, he makes it to be only a distinguishing principle, for he did not hold that the bodies that were mixed with one another received being from the separate intellect; they received from it only distinctions.

Plato

Plato therefore proceeded by a more adequate way to refute the opinion of these early naturalists. (Aristotle, Metaphysics, 1, 6–7 (987a 30–988b 16); 1, 9 (992b 7); III, 5 (1009a 38–1009b 33).) For since the early naturalists had held that man could not know the definite truth of things, both because of the continuous passing of corporeal things and because of the deception of the senses by which bodies are known, Plato posited certain natures, separate from the matter of flowing things, in which truth remained abiding. (Plato, Phaedo, 96A, 1001; Theaetetus, 156A; cf. Aristotle, Metaphysics, I, 9 (991b 3).) By adhering to these natures, our soul knew the truth. (Cf. St. Augustine, Liber LXXXIII Quaestionum, q. 46 (PL 40,30); Avicenna, Metaphysics, VII,2 (fol. 96ra).) Hence, as the intellect in knowing truth apprehends certain things beyond the matter of sensible things, Plato thus believed that there existed certain realities separate from sensible things. (Cf. A. C. Pegis, Introduction to St. Thomas Aquinas, xiii-xxx.)

Now, our intellect uses a twofold abstraction in arriving at the understanding of truth: one, according as it grasps mathematical numbers, magnitudes, and figures without the understanding of sensible matter. For in understanding the number two or three, or a line, a surface, a triangle, or a square, there is not included together with it in our apprehension anything pertaining to what is hot or cold (or the like) which is perceptible by sense. The intellect, however, uses another abstraction when it understands something universal without the consideration of something particular, as when we understand man without including in our understanding anything about Socrates, Plato, or any other individual. The same appears in other cases. (St. Thomas, Expositio super librum Boethii de Trinitate, q. 5, a. 1, ed. B. Decker, 161ff. (The Division and Methods of the Sciences, trans. A. Maurer, 3 ff).) Plato accordingly posited two classes of beings abstracted from sensible things: namely, mathematicals and universals, to which he gave the name of forms or ideas. (Aristotle, Metaphysics, VI, 2 (1028b 20); XII, 1 (1076a 20).) There appeared, however, to be this difference between them: namely, that in the case of mathematicals, we can grasp several members of one species (for example, two equal lines or two identical equilateral triangles), whereas with forms, this is absolutely impossible (man, for example, taken universally is only one in form). (Appropriation of form for species.) And so, Plato posited mathematicals between forms or ideas and sensible things, since mathematicals agree with sensible things in that many are contained in the same species, and they agree with the forms in that they are separate from sensible matter. (Aristotle, Metaphysics, I, 6 (987b 14–18).)

Further, he posited a certain order among forms themselves, on the ground that according as something was simpler in the intellect, so far was it prior within the order of things. Now that which is first in the intellect is the one and the good; for he understands nothing who does not understand one thing, and the one and the good follow upon each other. Hence Plato held that the first idea of the one, which he called the one-in-itself and the good-in-itself, was the first principle of things, and this idea he said was the highest good. (Plato, Republic, VI, 508C; Aristotle, Ethics, 1, 6 (1096a 22–23; 1096a 35–1096b 3); St. Augustine, De Civitate Dei, VIII, 8 (PL 41, 233); cf. Proclus, Elem, Props. 12, 13, 20, 119 (pp. 15, 17, 23, 105).) Under this one, he established among the substances separate from matter (Proclus, Elem, Props. 63, 129, 139 (pp. 61, 115, 123).) diverse orders of participating and participated beings, all of which orders he called secondary gods, (Nemesius, De Nat. Hom., 44 (PG 40, 793, 706); St. Augustine, De Civitate Dei, XIII, 16 (PL41, 388).) as being certain unities below the first simple unity. (Proclus, Elem, Props, 6, 14, 21, 116 (pp. 7, 17, 25, 103).)

Again, inasmuch as all forms participate in the one, the intellect likewise must participate in the forms of things in order to have understanding. (Cf. Proclus, Elem, Props. 114, 161 (pp. 101, 141).) Therefore, just as under the highest god, who is the prime unity, simple and unparticipated, other forms of things exist as secondary unities and gods; so, under the order of these forms or unities, he posited an order of separate intellects, which participate in the above-mentioned forms in order to have actual understanding. (Plato, Timaeus, 33A ff.; Aristotle, De Anima, 1, 3 (406b 25–407b 26); cf. F. M. Cornford, Plato’s Cosmology, 117 ff.; Proclus, Elem, Props. 129, 161 (pp. 115, 141).) Among these intellects, an intellect is higher according as it is nearer to the first intellect which has full participation in the forms; just as among the gods or unities, that one is higher which shares more perfectly in the first unity. Although Plato distinguished between the gods and the intellects, he did not mean to imply that the gods could not have understanding. It was his desire, rather, that they should understand in a supra-intellectual manner: that is, instead of understanding by participating in certain forms, they should have understanding through themselves, with the proviso that every one of them was good and one only through participating in the first one and good.

Again, because we see that certain souls possess understanding, which, however, does not befit a soul by the fact that it is a soul (otherwise it would follow that every soul is an intellect and that it would he intelligent in its whole nature), he further posited that under the order of the separate intellects there was an order of souls, the nobler of which participate in intellectual power, while the lowest of them are lacking in it. (This division into gods, intellects, and souls seems to be taken directly from Proclus, Elem, Props. 12, 13, 20, 113, 116, 119, 121, 184, 189, 190, 196 (pp. 15, 17, 23, 101–107, 161, 165,167, 171); cf. St. Thomas, In Librum de Causis, Props. 2 ff., ed. H. D. Saffrey, 10 ff.)

Again, because bodies do not seem to be capable of moving themselves unless they have a soul, Plato held that self-motion belongs to bodies insofar as they participate in soul, since those bodies lacking in this participation are not moved unless they are moved by another. Thus he considered it to be an essential property of souls that they move themselves. (Plato, Phaedrus, 246A; Proclus, Elem, Props. 20, 188, 201 (pp. 23, 165, 177).) In this way, below the order of souls, Plato posited the order of bodies, but in such a manner that the highest of the bodies, namely, the first heavens, which is moved by its own motion, receives motion from the highest soul, and so on to the very lowest of the heavenly bodies.

Below these, furthermore, the Platonists placed immortal bodies, namely, aëreal or ethereal bodies, which participate eternally in soul. Some of these they considered to be altogether independent of earthly bodies, and these they said to be bodies of demons; others became entombed in earthly bodies, which is the case with human souls. (Cf. St. Augustine, De Civitate Dei, VIII, 13, 16; IX, 8; XIII, 16 (PL 41, 237–247; 255–276; 387–389); On demons in neo-Platonic literature, cf. Proclus, Elem, 294–296; 313–321; St. Thomas, In Librum de Causis, Prop. 19, ed. H. Saffrey, 104–107.) For they did not believe that this earthly human body which we touch and see participates immediately in the soul; rather, there is another nobler body belonging to the soul, incorruptible and everlasting, even as the soul itself is incorruptible (Proclus, Elem, Prop. 196 (p. 171).) in such wise that the soul with its everlasting and invisible body is in this grosser body not as a form in matter but as a sailor in a ship. (Aristotle, De Anima, II, 1 (413a 8); St. Thomas, In De Anima, II, lect. 2, ed. Pirotta, no. 243 AACTA, 178); cf. Nemesius, De Nat. Hom., I, III (PG 40, 505; 593); Proclus, Elem, Props. 186, 187 (p. 163).) And just as they said that some men were good and others wicked, so too, with the demons. But they said the heavenly souls, the separate intellects, and all the gods were all good. (St. Augustine, De Civitate Dei, IX, 1, 2 (PL 41, 255–257).)

In this way, therefore, between us and the highest god, it is clear that he posited four orders: namely, that of the secondary gods, that of the separate intellects, that of the heavenly souls, and that of the good or wicked demons. If all these things were true, then all these intermediate orders would be called by us ‘angels,’ for sacred Scripture refers to the demons themselves as angels. (Matt 22:30; 25:41.) The souls themselves of the heavenly bodies, on the assumption that these are animated, should also be numbered among the angels, as Augustine determines in the Enchiridion. (St. Augustine, Enchiridion de Fide, Spe et Caritate, 58 (PL 40, 259–260); cf. A. C. Pegis, Cosmogony and Knowledge, I, 643–664; The Dilemma of Being and Unity, 179–183; St. Thomas and the Problem of the Soul in the Thirteenth Century, 147 ff.; St. Thomas and the Greeks, 9 ff.)