The Problem of Evil - Common Sense Atheism

Philosophical Failure 45
An argument for nominalism will be counted a success—this is
my proposal—if and only if an ideal nominalist can use it convert,
eventually to convert, an audience of ideal agnostics (sc. withrespectto
the existence of universals) to nominalism. And, of course, it is stipulated
that the conversion must take place under the following circumstances:
an ideal realist is present during the nominalist’s attempt to convert the
agnostics and will employ every rational means possible, at every stage
of the debate, to block the nominalist’s attempt at conversion.
A moment’s thought will reveal that, at this point in the debate, the
nominalist has, formally at least, a more demanding task than the realist.
The nominalist must convince the agnostics that the argument—the
argument whose effectiveness is being tested—is both valid and sound,
and the realist (the counsel for the defense, as it were: realism is in the
dock) need only cast doubt on either the validity or the soundness of the
argument. Or let us say this: need only cast doubt on the soundness of
the argument. The question of the argument’s validity can be eliminated
from the theoretical picture by the application of an obvious fact, to wit,
that formal validity is cheap: it can always be purchased at the price of
additional premises. Let us therefore imagine that all the arguments we
shall examine are formally valid (if they were not valid to start with, they
have been made valid by the addition of suitable additional premises),
and the debate is entirely about the truth-values of the premises of
the argument—or, more likely, about the truth-values of some of the
premises. Then the job of the nominalist is to convince the agnostics
that all the premises of the argument are true, and the realist’s job is
to convince the jury of agnostics to render a ‘‘Scotch verdict’’—‘‘not
proven’’—on one or more of those premises. I mean this criterion of
success in philosophical argument to be perfectly general, of course; it is
to apply to an argument for any (controversial) philosophical conclusion
whatever.
Looking at a ‘‘debate’’ this way has several advantages over looking at
a ‘‘debate’’ as an exchange in which two philosophers who hold opposed
views try to convert each other. A definition of philosophical success
based on the latter model of debate would allow few if any philosophical
arguments to count as successes. An argument for a thesis p would count
as a success only if an ideal debater could accomplish a very difficult task
indeed: to turn a determined and committed believer in the denial of
p into a believer in p by presenting him or her with that argument. To
revert to the example I have been using, an argument for nominalism
would count as a success only if an ideal nominalist could turn an ideal