Medieval Philosophy – Prof. Dr. Robert C. Koons

http://www.utexas.edu/cola/depts/philosophy/faculty/koons/phl349/syllabus.htm

Lecture # 27: The Problem of Universals: Ibn Sina and Aquinas

I. Ibn Sina

On the question of universals, Ibn Sina endorsed a form of realism that combined elements from Plato,
Aristotle, and Philo. He postulated three modes of the existence of universals:

1. In the mind of God: ante res (“before the thing”).
2. When clothed with accidents in a particular individual: in rebus (“in the things”).
3. When abstracted by the thinking mind: post res (“after the thing”).

II. Two Kinds of Being

Aquinas argues that there are two senses in which a thing can “be”: real and logical. A real being is either a
substantial thing (something that exists in its own right) or an accident that inheres in a substantial thing
(belonging to one of the other 9 Aristotelian categories, like quality, quantity, relation,…) For each real being,
there is a distinct act of existence whereby it actually takes up its place in nature or reality.

Logical being is a wider category, a weaker and looser sense of ‘being’. Everything that has real being also
has logical being, but not vice versa. Logical being corresponds to being the subject or topic of a true
sentence. A classic example of merely logical being is that of a privation or negation. For example, if I say
something like ‘darkness filled the room’, this looks superficially similar to a sentence like ‘carbon dioxide
filled the room’, but there is a critical difference: carbon dioxide has real being, while darkness has only
logical being. To say that that darkness filled the room is really to say that no light was present in the room.
There are also “accidental” privations. To say that Smith is blind or bald is not to speak of a real accident in
Smith, but rather the absence of a real accident of a certain kind (sight or hairiness). Smith’s baldness has
only logical being.

Logical being doesn’t mean that a thing is merely subjective, or that it is unreal in the sense of being merely
an illusion or fiction. There is nothing subjective, illusory or fictional about Smith’s blindness: he is “really”
(in the modern sense of the word) blind. In medieval Latin, the word ‘real’ still bears a connotation based on
its derivation from the word ‘res’ or ‘thing’. Instead of simply transliterating the word ‘real’ directly into
English, we should probably instead translate it as something like ‘thingish’. Then we could say that Smith’s
blindness has logical but not thingish being. It’s not illusory or fictional, but it isn’t, properly speaking, a real
thing.

Some contemporary philosophers have begun wrestling again with this metaphysical problem. There is a
commonly used slogan, ‘truth supervenes upon being’. This slogan means that we should be able to explain
the truth of any statement by reference to what is actually there, what really exists. This slogan could be
taken in two ways: (1) truth supervenes on logical being, or (2) truth supervenes on real being. In the first
sense, the slogan would be just a tautology (trivially true) for Aquinas. Whatever is involved in the truth of
any statement automatically and by definition has ‘logical being’. I think Aquinas would deny the slogan in
sense (2): there is no real being that makes it true that Smith is blind or that Kim has no children. It is rather
the absence of real beings of a certain kind (merely logical beigns), such as Smith’s sight or Kim’s children,
that makes statements like these true.

At the same time, Aquinas does state that a privation of being has its foundation in (real) being (Anderson
collection, p. 52). There is no such thing as absolute non-being (i.e., the absolute absence of real being). In
order for darkness to fill the room, the room must exist; in order for Smith to be blind, Smith must exist.
Privations always inhere in something: some substance or matter. However, the privation does not consist in
the presence of a positive (real) being.

Aquinas sometimes expresses this distinction as being-of-reason (something with logical but not real being)
versus being-of-nature (something with real being). Aquinas will use this distinction as the basis for a new
solution to the problem of universals.

III. The Problem of Universals

Every particular being (whether substance or accident) has both existence and essence. An essence is a
universal: it is shared by all the particulars whose act of existence is modified in the same way. Both Socrates
and Plato are men: they have a common essence. But what is an essence, and how can it be shared
simultaneously by several distinct things? As we’ve seen, there were a number of well known arguments
purporting to show that universals couldn’t possibly exist (we’ve already examined the ones presented by
Boethius and Abelard).

Aquinas accepts the critique of realism delivered by Boethius and Abelard. At the same time, he clearly
wants to avoid extreme nominalism. Like Aristotle, Boethius and Abelard, he takes it as obvious that things
have common natures. So, his position is some kind of intermediate one, either “moderate” realism or
“moderate” nominalism. (Traditionally, Aquinas has been classified as a “moderate realist”, but as we’ll see,
it’s not so obvious how to categorize these intermediate positions.) How can Aquinas sit on the fence? Either
universals exist or they don’t. What room is there for an intermediate position?

One solution to this dilemma is to turn to Aquinas’s distinction between real and logical being. We could say
that universals have logical being (contradicting the extreme nominalists) but deny that they have real being
(contradicting the extreme realists). Remember that logical being is not a form of merely fictional being. To
say that universals lack real being is not to claim that they are like Sherlock Holmes or unicorns: it is merely
to deny that they are “thingish” things.

The story is a little more complicated than this, however. Aquinas suggests that there are two ways of
thinking about an essence: (1) giving it “absolute consideration”, and (2) giving it considerations according
to the act of existence it has in this or that individual thing. When we are thinking about essences in the first
way, we are thinking about things with only logical being (beings-of-reason); when we are thinking about
them in the second way, we are thinking about real beings.

An essence-considered-absolutely, like man, is a merely logical being, a being-of-reason. It is not something
that exists as a thing, either substantially or dependently (as an accident). Still, one might argue, it must exist
in some sense, or else how could we think about it? Moreover, we can say things that are true of man and
other things that are false of it. For example, we can say truly ‘_Man_ is a species’ or ‘_Man_ is rational’, and
we can say falsely ‘_Man_ is a privation’ or ‘_Man_ is immaterial’. There has to be something out there, in
reality, that makes some of these statements true and others false. Finally, we have to be able to distinguish a
real nature, like man, from mere fictions, like Sherlock Holmes or the fountain of youth. Surely, man, the
essence-considered-absolutely, has to have some kind of real existence that these fictions lack.

I think Aquinas would agree with all this. So, the problem for Aquinas is this: how to avoid extreme realism?
In what sense does man-considered-absolutely lack real being? What does this mean, given that the essence
is not unreal?

The best answer, I think, must go something like this: the difference between a real thing like Socrates and a
being-of-reason like man consists in the fact that Socrates is logically complete in a way that man is not. We
can apply to Socrates a logical law known as the “law of the excluded middle”: if ‘_ is P’ is a predicate, then
we can say truthfully either ‘Socrates is P’ or ‘Socrates is not P’. Socrates is either asleep or not asleep, living
or not living, one or not one, a substance or not a substance, etc. However, the law of excluded middle does
not always apply to beings-of-reason, like essences-considered-absolutely. If we ask, “Is man one or many?”,
the question simply has no correct answer. Here are some other questions about man (considered absolutely)
that seem to have no answer:

• Is man a universal or particular?
• Is man a species?
• Does man actually exist?
• Is man asleep? pale? snub-nosed? happy? wise?

There would seem to be only a few sentences referring to man that are true: those that predicate to man
things that are either included or that necessarily follow from the definition of man.

• Man is rational.
• Man is an animal.
• Man is risible (capable of laughter).

There’s something very strange, however, about denying that we can truthfully say things like ‘_man_ is a
universal’ or ‘_man_ is a species’. The whole point of talking about essences-considered-absolutely was to
give us a way of attributing a kind of reality or being to universals. If we can’t even say ‘_man_ is a
universal’, we seem to have failed in this task. However, there is one more wrinkle to introduce. When we
talk about an essence considered according to its existing in particulars, there are two sub-cases to consider:
the existing of an essence in a thing actually having that essence, and the existing of an essence in the mind
or intellect. Consider first man considered as existing in Socrates. We can truthfully say:

• Man (as exemplified in Socrates) is wise.
• Man (as exemplified in Socrates) is a particular and has real being.
• Man (as exemplified in Socrates) is one, and not many.

Now, consider man as existing “in the mind”. An essence exists in the mind in the form of a concept or idea.
It is this concept or idea that is properly called ‘a universal’, according to Aquinas, since it is ideas (and
corresponding verbal phrases) that can be predicated of many things. Notice how similar this is to Abelard’s
position. Abelard’s sermones have been replaced with essences considered according to their existence in the
mind, and Abelard’s status have been replaced by essences considered absolutely. Otherwise, things are
very much the same. This is why it is difficult (if it is even possible) to distinguish clearly between moderate
nominalists like Abelard and moderate realists like Aquinas.

So, according to Aquinas, universals exist only in the mind. We can truthfully say:

• Man (as exemplified in my mind) is a universal, not a particular.
• Man (as exemplified in my mind) is a species.
• Man (as exemplifed in my mind) is many, and not one.

At the same time, there is something, namely the essence-considered-absolutely, a being-of-reason, that is
shared, both by all the individual men and by all the ideas of mankind.