3 4 5R e f u t a t i o n b y P a r a l l e l R e a s o n i n gHow can an opponent try to refute this argument? There are several
possibilities, but what defenders of gun control in fact did was distribute
other bumper stickers. One of them read:
(1*) If gum is outlawed, only outlaws will have gum.
The main point might be just to parody the NRA bumper sticker, but, if we
take it more seriously, (1*) also suggests an application of the method of refu-
tation by parallel reasoning. The parallel argument would continue like this:
(2*) It would be bad if only outlaws had gum.
(3*) Therefore, gum should not be outlawed.
This conclusion, however, is not obviously false. Indeed, it seems true:
People should be allowed to chew gum. Moreover, (2*) seems false, because
nothing particularly bad would happen if only outlaws chewed gum. For
these reasons, this bumper sticker cannot really refute the original argu-
ment. This failure illustrates two general tests: A refutation by parallel
reasoning works only if the conclusion of the parallel argument really is
unacceptable and only if the premises of the parallel argument really
are true.
But opponents of the NRA did not stop there. They distributed a third
bumper sticker:
(1**) If guns are outlawed, only outlaws will shoot their children by
mistake.
The argument behind this new bumper sticker is again not clear. If it is a
straightforward instance of refutation by parallel reasoning, then the paral-
lel argument would add, “It would be bad if only outlaws shot their children
by mistake” and conclude, “Guns should not be outlawed.” But that is the
very conclusion the NRA wants to reach; so this newest argument could not
refute the original one. Nonetheless, a different argument might lie behind
this third bumper sticker. The point seems to be that gun owners sometimes
shoot their children by mistake, and we can minimize such tragedies by re-
ducing the number of gun owners through laws against guns. The argument
then runs something like this:
(1**) If guns are outlawed, only outlaws will shoot their children by
mistake.
(2**) It would be good if outlaws were the only ones who shot their
children by mistake.
∴(3**) Therefore, guns should be outlawed.
This conclusion would seem false to the NRA, and this argument might also
seem to suggest that the same form of reasoning could lead to opposite con-
clusions: (3) and (3**). Moreover, (2**) seems true. This premise does not say
that it is good for outlaws to shoot their children by mistake. Instead, it says97364_ch17_ptg01_333-350.indd 345 15/11/13 11:12 AM
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