One of the interesting, and primordial, aspects of Thomistic philosophy is his Hierarchy of being. For Aquinas, as for many philosophers, Christian or otherwise, before him, the entire Universe can be arranged in a hierarchy based upon the types of being that are represented in it, and upon the way in which the different beings represent God. In this article, I do not wish to bring any new understanding, rather, in reading through The Philosophy of Thomas Aquinas by Étienne Gilson, I was impressed by the way in which he explained why God created a hierarchical universe. I have attempted to work out the basic arguments that Gilson brings, and will present them in the form of premises with one large argument containing two sub-arguments. Some of these thoughts may seem cryptic, as they are bathed in scholastic terminology. I’m sorry for the difficulty this may cause to some of my readers. For the definitions of some of the terms (form, matter, act, potency, etc.) that are used in this argument I would refer the reader to other blog posts that I have written. Following the argument I will include my interpretation of this hierarchy in picture form. The argument is as follows:
1. “Every Being that acts, tends to induce its likeness in the effect which it produces, and it succeeds the more perfectly, the more perfect it is in itself.”
2. “God is the supremely perfect agent.”
3. “It is, therefore, in conformity with His nature to induce perfectly His likeness in the things created.”
4. “It is evident that a single species of creatures would not succeed in expressing the likeness to the creator.”
a. Since the effect, which is finite, does not belong to the same order as the cause, which is infinite, “the effect of a single and solitary species would express only in the obscurest and most defective manner the cause from which it springs.”
b. “For a creature to represent as perfectly as possible its Creator, it would have to be equal to Him:”
c. “but this is a self-contradiction”
d. “In the case, on the contrary, of created and finite things, a multiplicity of such beings is necessary to express under the greatest possible number of aspects the simple perfection whence they flow.”
5. “Therefore, this multiplicity and variety were necessary in order to express as perfectly as created things can, the resemblance to their God and Creator.”
6. “To posit creatures of different species means necessarily to posit creatures of unequal perfection.”
7. “They can differ only in their matter or in their form.”
8. “The distinctions arising from a difference of forms, divide them into distinct species; the distinction arising from their diverse matter, constitutes individuals numerically distinct from each other.”
a. “Of incorruptible beings [pure intelligences – form that is not composed with matter], there exists only one individual of each species.” (Based on premise 8, form distinguishes species. Individuation – that by which there are many particular instantiations of one species – is due to determinate matter. Therefore, if X is form, but not matter – pure form, not composed with matter – then X is a species unto itself.)
b. In incorruptible beings, “there is neither numerical distinction nor matter, for the individual, being incorruptible, suffices to ensure the preservation and differentiation of the species.”
c. “In the case of beings which can propagate and die, a multiplicity of individuals is necessary to secure the preservation of species.”
d. “Beings exist, therefore, within a species, as numerically distinct individuals, only to enable the species to continue as formally distinct from the other species.”
9. “The true and fundamental distinction to be found in things lies in their formal distinctness. But, no formal distinctness is possible without inequality.”
10. “The forms which determine the various natures of beings, whereby things are what they are, are nothing else, in the last resort, but different amounts of perfection.”
11. “God, since it was impossible [based on premise 4 and the sub-argument] to express in a sufficiently perfect manner His likeness in a single creature, wishing to impart being to a plurality of formally distinct species, was therefore bound to produce unequal species.”
12. “Therefore we find in natural things that the species are arranged hierarchically and ordered in degrees.”
A couple remarks about the premises above. The first premise is a principle of the act that is accomplished between a cause and effect. The second premise is based upon the Thomistic arguments that prove that God exists, and which proceed to deduce certain truths about God, such as his perfection which is deduced from the fact that God is pure act. Premise three follows upon the first two premises. So far so good. Premise four is a key premise for the entire argument, and as such, is not immediately evident. Neither is it deduced from the first three premises. Therefore it must be proved. The four subpoints to the fourth premise attempt to show the truth of the fourth premise. Essentially, what is being argued is that, due to the nature of created being, it is impossible that one created being express perfectly its creator. This is because, by definition, a created being is finite, but the creator is infinite (this, as with the second premise is deduced from the Thomistic proofs that show that God exists.). In order to perfectly represent its creator a created being would have to be infinite which is a contradiction of terms. Therefore, premise 4 is true. Premise 5 is the logical consequence of premise 4. The sixth and seventh premises seem to be statements of fact. Premise 8 is a statement of fact, and the sub points go simply to illustrate and explain premise 8. Premise 9 and 10 seem to be based upon the definition of form. Premise 11 is based upon premise 4 and the sub points of premise 4. Premise 12 follows on the premises 1-11.
It must be remembered that this argument presupposes Aristotelian/ Thomistic Metaphysical categories and terms, as well as the Thomistic arguments that prove that God exists. It might also be remarked, that, in the following depiction of the Thomistic hierarchy of being, the hierarchy going from inanimate being to Human being is based upon observation. The hierarchy of the angels is based upon the above argument, and the necessity of proportion in any hierarchy. The gap between man and God is so great that it makes perfect sense that angels (pure spirits) exist to fill the gap. However, though all the various types of being from inanimate to pure spirit exist, there is still an unbridgeable gap between the highest and most perfect being in the hierarchy, and God. There is so much more that could be said, however I will finish with one final observation. The being of all the various types of being in this hierarchy receives their existence from God alone, and are held in existence by God alone. The reason for their existence is to represent and glorify God.
In the Illustration below (which I had fun trying to include in this post. Sorry for the pitiful picture.), some may find the hierarchy of the angels a bit strange. A couple of remarks are necessary on this subject. First of all, Aquinas does not pull the hierarchy of the angels out of the Bible, but bases it upon philosophical arguments. He does claim that due to the fact that the Bible claims that angels exist, and due to the fact that the Bible is the word of God, therefore we can be certain (due to the nature of the authority – God) that angels exist. As for the various titles given to the levels, I can make no commentary as to whether they are necessary titles or not, I would assume that they are simply titles of convenience. Secondly, we should not reject such a hierarchy simply because we are uncomfortable with it. Rather, in order to rationally, with all intellectual honesty, be able to reject such a claim, one must first examine the arguments that are given for the claims made. A summary of the arguments can be found in the book quoted above, in the 8th chapter.