Disputation 5, Section 1:
Are all things that exist or are able to exist singular
- I. Reasons for doubting an affirmative answer (n. 1)
- A. The case of God: The divine nature is communicable to the
three divine persons, in the same way that the common nature human being,
which is not a singular entity, is communicable to many individuals.
- B. The case of angels: Angels have only specific or essential
unity and not numerical or singular unity. So each angel is akin to what
the common nature human being would be if it existed on its own
- C. The case of common natures as existing in individuals: The
common nature human being exists in Peter and Paul and is not as
such a singular thing.
- II. An analysis of the notion of individual (or singular or numerical)
unity (nn. 2-3)
- A. Analysis: That which is singular or individual is opposed
to that which is common or universal (i.e., that which has specific or
generic unity rather than numerical unity) in the sense that that which
is singular or individual "is one in such a way that, under that notion
of being by which it is called one, it is not communicable to many as to
things which are [logically] inferior to or subordinated to it, or to things
which are many within that same notion." For instance, the common
nature human being lacks singular unity because it is communicable
to and common to many humanities (Peter, Paul, Joan, etc.) which share
the same notion, viz., human being. By contrast, Peter, i.e., this
humanity, is not common to many individuals which share the notion this
humanity. Also, Peter and Paul are subordinated to human being
in the sense of falling under it as determinates under a determinable.
So what is distinctive about numerical or individual unity is the negation
of a certain sort of divisibility, viz., divisibility of a determinable
into lower-level determinates.
- B. Amplification: "Singular entitas is such that
it is not the case that its whole notion (ratio) is communicable
to many similar entitates, i.e., divisible into many entitates
which are such as it itself is." Note that even per accidens
unities (e.g., a heap of stones), numbers greater than one, and common
natures (i.e., genera and species) themselves have a sort of individuality.
But they do not have full-fledged singular unity because they are not per
se entities, i.e., entities that as such have natures capable of existing
`in an unmediated way'. "So the notion of per se individual
and singular unity consists in entitas that is by its nature one
per se and is undivided or incommunicable in the aforementioned
- III. the resolution of the question (nn. 4-5)
- A. The answer: "Given that the notion of an individual
or singular being has been explicated in the above way, one should claim
that all things which are actual beings, i.e., which exist or are able
to exist in an unmediated way, are singular and individual. I say `in an
unmediated way' in order to exclude the common natures of things, which
cannot as such exist in an unmediated way or have actual entitas
except within singular and individual entities--the latter being such that
if they are destroyed, then it is impossible for anything real to remain."
- Question: Given this, what distinguishes common natures from accidents?
- (1) Whatever exists has a fixed and determinate entitas.
- (2) But every such entitas has an added negation.
- Therefore, every such entitas has singularity and individual
- Proof of (2): Every entitas, by the very fact that it is a determinate
entitas, is unable to be divided from itself; therefore, every entitas
is also such that it cannot be divided into many entitates which
are such as it is (since otherwise the whole entitas would be in
each of them and so it would, insofar as it exists in one of them, be divided
from itself insofar as it exists in another--which is manifestly absurd).
- According to Suarez, this argument shows that universals cannot exist
in reality separate from singular things. The argument depends crucially
on the rhetorical question: How can a universal be truly predicated of,
or essentially constitute, a singular thing unless it exists in that thing?
That is, how can the essence or nature of a given thing be something separate
from it that does not exist within it? This is precisely the question that
many modern-day Platonists answer with a resounding: "Easy! That's
just the way it is."
- IV. Reply to original reasons for doubting an affirmative answer
- To A: The divine nature is singular and is communicable to the
persons not as a superior to an inferior (or species to an individual),
but in the manner of a form to a suppositum. The nature is not divided
from itself, but instead is whole in each of them. Note, then, that the
relation of the divine nature to the three divine persons is not
to be thought of as like the relation of the common nature human being
to Peter, Joan, and Paul. It's rather as if the same singular humanity
were each of Peter, Joan, and Paul. This is why the Trinity is mysterious.
- To B: Some Thomists think that spiritual natures are like abstract
specific essences, but this will be discussed later. In the meantime, we
simply deny that angelic natures are anything other than singulars, and
this independently of how one answers the question of whether an angelic
nature can be multiplied in many individuals within the same species.
- To C: Human being, as it exists in reality, is singular,
since it is nothing other than Peter, Paul, etc. But whether it is in any
sense distinct from the individuals will be discussed in the next chapter.
- V. Three separate questions concerning individuation
- A. The individuality question: What is the intrinsic principle
by virtue of which a thing of a given species, say the species aardvark,
is this aardvark or numerically one aardvark or an individual
aardvark? That is, what constitutes it as something which is, as the Latin
term individuum suggests, indivisible into things each of which
shares the very same notion?
- B. The distinctness question: Given a pair of individuals of
the same species, what is the intrinsic principle by virtue of which this
one is distinct from that one? (Note that distinctness is different
from individuality or numerical unity, since distinctness, unlike individuality,
is a relation that presupposes the existence of at least two individuals.)
- C. The plurality question: What makes numerical plurality within
a given species possible? That is, what is the metaphysical ground for
the possibility that there should exist more than one individual of a given
species? (This question is obviously different from the individuality question,
since it is conceivable that an individual should belong to a species that
cannot be multiplied into many individuals; this, of course, is just what
St. Thomas himself believes to be true of the angelic species. The plurality
question also differs from the distinctness question, even though they
are intimately related; for the distinctness question has a place only
on the assumption that there is a plurality of individuals within a given