The following comprises a very brief sketch of how to begin the science of metaphysics as I understand it thus far, in light of my study under John Nieto. Anything that is true and clear, herein, must be directly credited to his teaching. Any errors or ambiguity are all my own. Please comment if possible and present any questions that might occur to you, as this will help further my understanding and clarity on the matter, and allow me to pose questions that I cannot answer to our teacher.


I will put aside at this point, the first question that is dealt with by Aristotle, the need for a science that is wisdom. The only reason for this, is that I believe that is sufficiently intelligible to my mind and to yours, fellow quaerentes. As interesting as the question is, in itself and to me; and though I am certain to profit from greater inquiry into the question, what immediately is on my mind is considering the subject of metaphysics. There are two principle questions that arise: 1.) How can the proposed subject of metaphyscis, ens, be a genus? 2.) How can it be one? These questions might, in the end be the same question, but at least at this point it seems helpful to consider them distinctly as it will bring clarity to our understanding. This has the added benefit of familiarizing us with something that metaphysics is concerned with, perhaps more than any other science, considering separately things that are one.

I. We are, then, seeking a science of being. Of things that are, it is clear that there are those things that exist per se, and those that things that exist only accidentally (i.e., white man), or secundum quid, (i.e., non-being, or potential being) . The science that we seek will certainly consider all of these kinds of beings, but we are principally concerned with things that exist per se, since such things give rise to the others.
1. The things that we see exist per se are:
1. Substances
2. Accidents
3. Mental Being
4. The Soul (maybe, or in a certain respect)
5. The first mover
2. Each of these things seems to exist in a different way. For now, for clarity (and because I don't understand these matters fully) we will put aside mental being and immaterial being. These are of course important, but are not necessary to consider in order to see that we can consider ens as the subject of our science. (N.B. Settling this question, by no means settles the question as to whether a science of metaphysics is possible. It is merely among the first in a long series of questions that must be answered.)

DIGRESSION: An interesting digression that we will do well to bear in mind. This was pointed out to me by John Nieto: Consider St. Thomas' work De Ente et Essentia. If the distinction in metaphysics is between esse and essentia, then why isn't that the title of St. Thomas's work? The answer: esse can never be considered as a subject. Existence is always in the predicate position in our speech and understanding. I believe that this is a very profound truth, that reveals a great deal about the way we know, and exist. We cannot consider existence as subject, we always must consider somethhing as existing or having existence. ~end digression

II. We are able to see that there is some ens that is apt to exist substantially. This being we understand as what exists through another. This is the definition of substance.
III. There are other entes that are such that they exist in another. Such beings are called accidents.
IV. Therefore he have
1. ens that exists through another.
2. ens that exists in another
1. ens is the subject of our thought and speech and of existence. It is not a predicable.
2. existence is never the subject, but is always a predicable (The same is manifestly true of the the other kinds of beings, i.e. mental and immaterial beings).
V. Therefore, for ens to be a proper genus for our science, it must not be considered as a predicate genus, but as a subject genus.
VI. A subject genus differs from a predicate genus in this way.
1. A subject genus is actualized or determined by something in a different category, or more properly, a subject genus is a whole with respect to another whole.
2. A predicate genus is actualized or determined by something in the same category. It is a whole with respect to its parts.
1. Example from mathematics
1. Figure is a predicate genus. It is actualized by being determined as this kind of figure or that. It is a whole with respect to its parts, namely the various kinds of figures. Thus, a circle and a triangle are two different figures.
2. Surface is a subject genus. It is a whole with respect to all figures. The determination that it has is by another kind of being, namely figure. (Surface belonging properly to the category of quantity, and figure belonging to the category of quality). A circle is not another kind of surface than a triangle. Rather, it is a surface that is supposed under this sort of figure, namely one in which its boundary lies at an equal distance from its' center, etc...
VII. Ens is, therefore a subject genus. Substance and accidents are not different kinds of entes, in the sense that ens is divided into these as parts. Rather,
1. A substance is an ens that is supposed to exist through its accidents.
2. An accident is an ens that is supposed to exist in a substance.
Therefore ens is a genus.
My notes/thoughts on the second question will follow shortly.