Simple
Substance
A simple substance is a substance that lacks parts.
But what is a substance? Many
proposals have been given. Here is a proposal that makes the most sense to me:
(1) A
substance is a thing (a Being) that (i) cannot be exemplified and
(ii) has no parts that can be exemplified.
Philosophers, Hoffman and Rosencrans,
would take issue with (1) on the grounds that there may properties that cannot
be exemplified. Such properties would then count as substances. (See Substance:
its Nature and Existence.) My reply is that every property that cannot be
exemplified—such as, being a square circle—is actually a complex (arrangement) of properties that can be exemplified. So impossible properties pose
no counter-example to this account. Hoffman and Rosencrans
may reply that my account isn’t theoretically
neutral. If someone thinks that properties that cannot be exemplified are not complexes of properties that can be,
then she will not accept my definition. The idea is that a definition of
‘substance’ should not presuppose controversial metaphysical views about the
nature of properties. But I reply that my definition grows out of my
understanding of how to define terms
like ‘property’, and so I suspect that it isn’t even a conceptual possibility that being a square circle, say, isn’t a
complex of properties. From where I’m standing, it’s merely a conceptual
possibility that it’s a conceptual possibility that being a square circle isn’t a complex of properties. If a
second-order conceptual possibility were sufficient to motivate a more neutral
definition, then surely no definition of any term could ever be neutral enough!
So, I’m content to accept (1) as sufficiently neutral in the context of my full
theory of the categories.
Side note: Hoffman and Rosencrans
account of substance crucially relies on the term, ‘level C category’, but I do
not grasp what they mean by that term.
A neglected duty of metaphysicians is to find out
true principles about the kind, Substance. Here is an obvious, but
uninteresting example:
(2) No
substance exemplifies another substance
Proposition (2) is a theorem because it can derived
from (1). It may also seem that
(3) No
substance depends for its existence on the non-existence of any other substance
And that
(4) Every
substance has properties.
But less obvious, perhaps, are these:
(5) No
substance could spatially overlap another substance.
(6) No
substance could begin to exist without being caused to begin to exist.
(7) Substances
cannot have temporal parts.
(8) Being a substance
and existing necessarily are
compatible properties.
Part of the job of a metaphysician is to investigate
principles of substances in general. (For potential reasons to accept (8), for
example, see Necessary Concreta.)
This is an important job in part because insights into the nature of substances
in general can help us to better understand the pros and cons of the more
fundamental theories in physics. Physicists are keen on the theoretical virtue
of simplicity, but some physicists may be less keen on certain insights that
can be gained by studying relations between various essential properties of
substances. There are arguments in the philosophy of time (why isn’t there a
branch called the philosophy of substance?), for example, that may add
additional conceptual data to consider when giving a metaphysical
interpretation of “time-dilation” (say) in the special theory of relativity. Or
consider that philosopher E.J. Lowe think that an inquiry into the nature of
identity can aid our understanding of what interpretations in quantum mechanics
are genuine metaphysical possibilities. My own thought that is that
philosophers have lot to contribute in terms of adding additional conceptual
data to consider when weighing alternative ontological interpretations of the
data.
I think that one could, in principle, lay down some clear axioms of substances in
general and then hand these axioms over to logicians or mathematicians for them
to derive further theorems. Maybe one day, a math textbook will be devoted to
Substances. Think of it this way. Substances can exemplify shapes, and they come in quantities.
Geometry is the branch in math that studies shapes, and number theory studies
quantities. Why couldn’t there be a branch that studies substances, once more
of the axioms are laid down? I suspect it’s too early in the evolution of human
civilizations to rule that out.
Here are some further questions about substances worthy
of investigation:
(9) Should
there be an explanation as to why there are any substances in the first place?
(10) Could a substance
endure through the elapsing of an infinitely many discrete units of time?
(11) Are substances “bundles”
of properties? Answer: No.
(12) Are substances
composed of both matter and form? Answer: No
The answers to (11) and (12) are actually derivable
from the definition of ‘substance’ that I gave above, which entails that no
substances have properties (or forms) as parts.