Aristotle on substance
In the Physics, Aristotle famously
distinguishes between natural and artificial objects. Some examples of natural objects would be
stones, copper, trees, and dogs. Some
examples of artificial objects would be tables, paintings, automobiles, and
computers. Or to take an example I like
to use, a liana vine (the kind Tarzan swings around the jungle on) would be a
natural object, and a hammock Tarzan makes out of living liana vines so as to
nap in the afternoon would be an artifact.
different ways to explain the distinction.
Aristotle characterizes natural objects as those whose principle of
change and stability is internal to them, whereas artificial objects have their
principle of change or stability imposed from outside. For instance, a liana vine’s tendencies to
sink roots into the ground, draw water in through them, and grow upward toward
the forest canopy all arise from within it.
But the hammock made from living liana vines will maintain the proper
shape, remain tied together, etc. only if Tarzan continuously maintains it by
retying vines that have come apart, pruning them, and so on.
to make the distinction is to note that natural objects have substantial forms, whereas artifacts
have merely accidental forms. The mark of a thing’s having a substantial
form is the presence of properties and causal powers that are irreducible to
the sum of the properties and powers of its parts. Something having a merely accidental form, by
contrast, has properties and causal powers that are reducible. For example,
the distinctive properties and powers of a liana vine cannot be analyzed as
merely a sum of the properties and powers of its parts (such as the cells,
molecules, or atoms of which it is composed).
But the properties and powers of a hammock can be reduced to the properties and powers of the vines it is made
out of, together with Tarzan’s intention of using the vines to function as a
A third way
to make the distinction is to note that natural objects have intrinsic or built-in teleology, whereas
artifacts have merely extrinsic or
externally imposed teleology. The
tendencies of liana vines to sink roots into the ground and to grow upward
toward the forest canopy are intrinsic to them, whereas their tendency to function
as a hammock is externally imposed by Tarzan.
ways of making the distinction are closely related. A natural object’s intrinsic teleological
features follow from its substantial form, and are manifested in the operation
of its distinctive causal powers. For
instance, the substantial form distinctive of a liana vine manifests itself in
the vine’s being directed or aimed toward the ends of sinking roots into the
ground, growing upward toward the forest canopy, etc. And the change and stability distinctive of
such a vine is manifest in the operation of the causal powers by which the vine
realizes these ends.
the externally imposed end of functioning as a hammock determines which
accidental forms Tarzan has to put into the vines (tying them this way rather
than that, pruning them of these bits but not those) so that it will exhibit
causal powers facilitating that end (e.g. the power to support the weight of an
adult human being).
physical substance, for the
Aristotelian, is an object that has a substantial
rather than merely accidental form; which, accordingly, exhibits certain intrinsic rather than merely externally
imposed teleological features; and which thereby manifests certain inherent
patterns of change and stability. Artifacts
are not true substances, precisely because they have merely accidental forms,
externally imposed teleology, and patterns of change and stability that are not
entirely inherent to them. Hence a liana
vine is a true substance and a hammock is not.
(I say more about the distinction between the natural and the artificial
in my recent essay “Natural and Supernatural,” in the Simpson , Koons, and Orr
Metaphysics and the Theology of Nature.)
artifact is not the only way to fail to be a true substance, though. This is where aggregates come in. Suppose
Tarzan ties a hammock between two trees, but later abandons and forgets about it. Imagine the vines that make it up die, and
the whole thing comes loose and drops to the ground, forming a pile beneath the
trees. Imagine that the vines come
completely untied, dry out and fade, and take on the appearance of an amorphous
mass or random tangle. Since the vines
are dead and no longer exhibit the distinctive properties and powers of liana
vines, they are on the Aristotelian view not strictly liana vines any longer at all.
They are substances of some other kind instead – bits of fiber,
say. And since the pile no longer has
the distinctive features of a hammock (and Tarzan no longer even intends to use
it as such) it is no longer a hammock either.
it? It is an aggregate of these new fibrous substances – a collection whose
powers and properties are reducible to the sum of the parts of the
collection. It is like an artifact,
except that an artifact has a teleology imposed from outside by some mind,
whereas an aggregate does not. This is
so even if it behaves as if it
did. For example, imagine that the pile
of dead vines prevents water from flowing between the trees the hammock had
fallen from. It functions as if it were a dam, but it is not
strictly a dam since it was not built for that purpose (either by human beings
or beavers, say).
Searle on intentionality
now to Searle’s distinction. Intentionality is a technical term for
the directedness or “aboutness” characteristic of mental states and of
linguistic and other sorts of representations.
For example, your thought that the
Eiffel Tower is in Paris is about
or directed towards a certain object
– the Eiffel Tower. The English sentence
“The Eiffel Tower is in Paris” is also about
or directed toward the Eiffel
Tower, as is a painting of the Eiffel Tower.
By contrast, a random string of letters like “gjaargrvma,” or the
splotches on the ground that form when you accidentally spill some ink, have no
intentionality. They are not about anything, but are mere meaningless
Searle points out in several places (such as his book The
Rediscovery of the Mind), these examples illustrate two different kinds
of intentionality. The string of letters
that make up the sentence “The Eiffel Tower is in Paris” has intentionality,
whereas the random string “gjaargrvma” does not. But notice that the intentionality of the
first string is not inherent to
or all on their own, the first set of letters is as meaningless as the
second. It’s just that, given the conventions
of English usage, the first conveys a sentence and the second does not. Absent those conventions, the first would be
as devoid of intentionality as the second or as an accidental splotch of ink.
thus have what Searle calls derived
intentionality. So too does a
drawing of the Eiffel Tower, and representations of other kinds such as symbols
(for example, the symbols making up a “No smoking” sign). Now, the source of this derived intentionality
is the human mind. The sentence “The
Eiffel Tower is in Paris” has the meaning it does because it is used to express
the thought that the Eiffel Tower is in Paris.
Thoughts, however, do not in turn derive their meaning from anything
else. We use sentences to convey the contents
of thoughts, but nobody uses thoughts to convey the contents of thoughts or of
anything else. Thoughts just are their contents, as it were. They have their meaning in a built-in
way. They have intrinsic (or original) rather
than derived intentionality.
Scholastic writers like John Poinsot put this is to say that sentences are instrumental signs whereas thoughts are formal signs. An instrumental sign is a sign that is also
something else – a set of ink marks, a noise, an image, or what have you. Its content is something additional to or
distinct from these other features, and that is why for such features to have
any content at all requires that the content be derived. A formal sign is a sign that is nothing more than a sign, and in particular
nothing more than its content. It just is its content, which is why its content
is intrinsic rather than derived.)
notes that there are phenomena that do not have intentionality of an intrinsic
or even a derived kind, but which it is nevertheless useful to describe as if they had it. For example, when seeing dark clouds we might
say “Those clouds mean that it will rain.”
Naturally, the clouds don’t have such a meaning in the way that the thought that it will rain has meaning.
For the clouds aren’t thinking.
But neither do the clouds have meaning in the way that the sentence “It
will rain” does or in the way that a drawing of rain does. A cloud is not a sentence, or a picture, or a
symbol, or a representation of any other kind.
Rather, what is going on is that, since we know there is a causal
correlation between dark clouds and rain, we infer from the presence of the
clouds that there will be rain. The
meaning (in the sense of the conceptual or semantic content) is in us, not in the clouds. But describing the clouds as if they had
semantic content is a useful shorthand.
Searle calls this as-if
intentionality, but emphasizes that precisely because it is only as if the
phenomenon had intentionality, it is not strictly a kind of intentionality but
a convenient fiction. Another example
would be when we say that the water wants
to get to the bottom of the hill (as if water really wanted anything).
intrinsic intentionality is the most basic of the three. Derived intentionality exists only because
there is intrinsic intentionality to derive it from. And as-if intentionality is a matter of
speaking of a thing as if it had the intrinsic intentionality that thoughts
have or the derived intentionality that words and the like get from the
intrinsic intentionality of thoughts.
is a parallel between natural substances, artifacts, and aggregates on the one
hand and intrinsic intentionality, derived intentionality, and as-if
intentionality on the other. Consider
first that natural substances are more fundamental than artifacts and
aggregates, because the latter presuppose the former. In particular, an artifact is essentially a
natural substance or collection of natural substances that have been arranged
by someone to realize some end of his (such as Tarzan’s hammock). And an aggregate is a collection of natural
substances that might superficially appear as if it were a natural substance or
an artifact but is not, since it lacks the purposes of either (as in the case
of the pile of dead vines).
intrinsic intentionality is more fundamental than either derived or as-if
intentionality. Like an artifact,
something with derived intentionality (such as words, images, or symbols)
reflects the purposes of some agent.
Like an aggregate, something with as-if intentionality can seem like it
reflects such purposes but does not.
for the parallel has primarily to do with the different kinds of teleological features exhibited by the different
kinds of physical objects. Teleology essentially
involves directedness toward an end
or goal. But intentionality also
involves a kind of directedness, namely directedness toward an object of
representation (whether representation in thought, in words, or whatever). The key difference is that intentionality
involves directedness of a mental kind, whereas teleology need not (though it
can). For example, the directedness of a
liana vine to the ends of sinking roots into the ground, growing toward the
forest canopy, and so on is in no way conscious or otherwise mental. For a liana vine has no mental properties of
If we think
of directedness as the generic
feature that both physical objects and intentionality can possess in different
ways, then what the members of the two sets of distinctions have in common is
this: natural substances and intrinsic intentionality both involve an inherent or built-in directedness;
artifacts and derived intentionality both involve a borrowed or derivative directedness; and aggregates and as-if
intentionality both involve no genuine directedness at all, but at most only
the appearance of it.
parallels also manifest themselves in the way Aristotelians and Searle would
object to the notion that the human mind is literally a kind of computer. The Aristotelian would say that rational animals
are substances of a kind, whereas computers are a kind of artifact. The former have substantial forms, intrinsic
teleology, and irreducible causal powers; whereas the latter have merely
accidental forms, derivative teleology, and reducible causal powers. So, it is just a category mistake to think of
the mind as a kind of computer. Similarly,
Searle has argued that minds have intrinsic intentionality, whereas computers
have only a kind of derived intentionality.
(Actually, the relationship between Aristotelianism and Searle vis-à-vis
computers is somewhat more complicated than this. I have discussed it in detail in my Nova et Vetera article “From Aristotle to John
Searle and Back Again: Formal Causes, Teleology, and Computation in Nature.”)
of the parallel I’m calling attention to is at least implicit in some comments
Daniel Dennett makes in his essay “Evolution, Error, and Intentionality” (from
his collection The
Intentional Stance). Following
W. V. Quine and others, Dennett holds that the meaning or semantic content of
thoughts and utterances is indeterminate
from the physical facts about human beings and their larger environment. That is to say, if the physical facts are all
the facts there are, then there simply is no
objective fact of the matter about what any of our utterances mean or about
the content of any of our thoughts. (Recall
Quine’s famous “gavagai” example.) Since
these thinkers hold that the physical facts are indeed all the facts there are,
they conclude that there is indeed no fact of the matter about what we mean
when we say or think something.
Now, I have
argued (in my American Catholic Philosophical
Quarterly article “Kripke,
Ross, and the Immaterial Aspects of Thought” and elsewhere) that while the
premise about the semantic indeterminacy of the physical is true, the
conclusion Quine, Dennett, and others draw from it is false, and indeed
incoherent. The right conclusion to
draw, I submit, is that thought is not physical. But for present purposes we can put that
aside. What I want to call attention to
here is that Dennett notes (at p. 321 of his essay) that (given his
naturalistic assumptions) there can be no objective fact of the matter about natural functions any more than there
can be about the meaning or semantic
content of thought. That is to say,
the same considerations that entail the indeterminacy of semantic content also entail
indeterminacy about the teleological properties of natural objects. Just as, for Quine, there is no objective
fact of the matter about whether “gavagai” means “rabbit” or “undetached rabbit
part,” so too there is no fact of the matter about whether the function of the heart
is to pump blood.
Now this position too, as I argue in chapter 6 of Aristotle’s Revenge, is ultimately incoherent. Teleological notions simply cannot be eliminated from biology, and if that result is incompatible with naturalism, then that is just another reason to reject naturalism. But even if you disagree with me about that, the point for present purposes is that Dennett’s position reinforces the idea that there is a parallel between the Aristotelian’s teleological notion of a natural substance and Searle’s notion of intrinsic intentionality. For it is precisely because of this parallel that Dennett (who is no fan of either Aristotelianism or Searle) wants to reject both of them together.