PHI 2010
Sample Paper
In the Argument from Possibility and Necessity, Aquinas argues that there must be a
God. He takes it as a premise that some things could have failed exist and that this implies that
those things once did fail to exist. He then argues that if everything could fail to exist, it follows
that there was a time when there was nothing, which is absurd, since there is something now and
something cannot come from nothing. He concludes on these grounds that there must be things
that exist necessarily—one of them being God.1 Mackie criticizes Aquinas on the grounds that it
is perfectly conceivable that there is a contingent stock of matter/energy that has no origin at all
and hence always existed.2 If such an object is possible, this would count against Aquinas’ proof,
since Aquinas thinks that contingently existing objects, as such, must have finite history. I argue
that Mackie’s claim that an uncaused stock of matter/energy is possible is rather questionable.
There is good reason to believe that all objects that exist contingently have their origins
essentially.
Take some examples. Consider an individual oak tree that came from a particular acorn.
Could that very oak tree have come from a different acorn? No. Any oak tree that came from a
different acorn could not be that very acorn. At best, it would be a kind of duplicate. Now take
Socrates. Could Socrates have come from different parents? No. Anyone who came from
different parents would have to be someone other than Socrates—perhaps an uncanny lookalike.
Each of these examples involves an object that must have the very origin it has. Neither could
have come from somewhere else, and neither could have come from nowhere. Why think of the
stock of matter/energy any differently?
Mackie does not tell us. But he would, perhaps, reply to my argument by noting that each
of these examples involves a living thing, in which case my examples show only that living
things have their origins essentially. But consider a particular volcanic rock. It is not a living
thing. Could it have come from a laboratory rather than a volcano? No. It originated, essentially,
in a volcano. Perhaps a duplicate rock could be produced in a laboratory, but not the particular
rock in question. It had to originate in a volcano, and any rock produced in a laboratory had to
originate in the laboratory (or at least in the equipment that belongs to the laboratory but could
have been somewhere else).
Mackie might reply to all of this by saying that it shows only that if a given object has an
origin, then it is indeed essential to it that it has that origin, from which it does not follow that all
objects must have an origin. Weakening the generalization about origins in this way
accommodates Mackie’s claim about the possibility of a stock of matter/energy without an
origin. However, we have not been given an independent reason for accepting this weaker
generalization about origins in place of the first. What makes the stock of matter/energy different
from the other contingently existing objects we have considered? Mackie doesn’t say, and he
owes us an answer.
----Commentary:
1
2
J.L. Mackie. Critique of the Cosmological Argument, p. 194. PHI 2010 pdf file.
Ibid., p. 194-5.
1
The paper gets right to the point. The first paragraph contains no BS about how many thousands
of years we have been wrestling with such questions. The paper doesn’t insult Mackie by saying
how weak and worthless his arguments are, and it doesn’t contain any pointless self-praise to the
effect that it destroys Mackie’s arguments once and for all. It simply engages him in a kind of
dialogue and represents the author as having come out on top.
Some of the paper is in the first person. That is fine and is the norm in philosophy. The paper
doesn’t contain a single big word, and the sentences are not too long. Also, the paragraph breaks
correspond to the flow of ideas.
By no means does the author prove Mackie to be wrong. But the author does play the role of an
honest and reasonable participant in a conversation in which Mackie is taken to task.
2