Edward Feser on Ad Hominem!
- Ad hominem often comes up in the cases of controversies, and I am often falsely accused of the fallacious use of ad hominem, my accusers typically indicating that alleging the use of ad hominem automatically implies a fallacy.
I typically respond by simply noting that there is the non-fallacious ad hominem which I often use.
I just ran across an exposition of that issue on Feser's blog and present it for consideration here:
What is an ad hominem fallacy?
Thursday, April 18, 2013
As students of logic know, not every appeal to authority
is a fallacious appeal to authority.
A fallacy is committed only when the purported authority
appealed to either does not in fact possess expertise on
the subject at hand, or can reasonably be supposed to be
less than objective.
Hence if you believed that PCs are better than Macs
entirely on the say-so of either your technophobic
orthodontist or the local PC dealer who has some overstock
to get rid of, you would be committing a fallacy of appeal
to authority -- in the first case because your orthodontist,
smart guy though he is, presumably hasn't much knowledge of computers, in the second case because while the salesman
might have such knowledge, there is reasonable doubt about
whether he is giving you an unbiased opinion.
But if you believed that PCs are better than Macs because
your computer science professor told you so, there would be
no fallacy, because he presumably both has expertise on the
matter and lacks any special reason to push PCs on you.
(That doesn't necessarily mean he'd be correct, of course;
an argument can be mistaken even if it is non-fallacious.)
Similarly, not every ad hominem attack -- an attack "against
the man" or person -- involves a fallacious ad hominem.
"Attacking the man" can be entirely legitimate and sometimes
even called for, even in an argumentative context, when it
is precisely the man himself who is the problem.
Attacking a person involves a fallacy when what is at issue
is whether some claim the person is making is true or some
argument he is giving is cogent, and where the attacker
essentially ignores the question of whether
the claim is true or the argument cogent,
and instead just attacks the person giving
it (in which case we have a kind of red
herring fallacy) or
suggests either explicitly or implicitly
that the claim can be rejected false or the
argument rejected as not cogent on the basis
of some irrelevant purported fault of the
person giving it (in which case we have a
poisoning the well fallacy, or perhaps a tu
Hence, suppose you put forward an argument against
"same-sex marriage" and someone responds either by
calling you a bigot, or by suggesting that the only
reason you are putting forward such an argument is
to rationalize some religiously motivated prejudice.
Here we have classic examples of ad hominem fallacies.
In the first case the person responding to you is
trying to change the subject -- trying to make you
and your alleged bigotry the issue, where what is
at issue is the cogency of your argument.
In the second case, the person is not changing the
subject -- he is addressing the question of whether
your argument is cogent -- but he is nevertheless
appealing to an irrelevant consideration in assessing
its cogency, since whether your argument is cogent or
not has nothing essentially to do with your motives
for putting it forward.
However, if what is at issue is not a person's claim
or argument, but rather precisely some aspect of the
person himself, there is no fallacy in calling attention
to his defects, and in some cases it can even be entirely
appropriate to do so in a polemical fashion.
For example, suppose what is at issue is whether a certain
person is a reliable witness or an unbiased source of
information, as in a court case.
Then there is no fallacy whatsoever in showing that his
track record reveals him to be a compulsive liar, or to
have a bad memory or bad eyesight, or to have been drunk
at the time of the events he claims to have witnessed,
or to have a personal stake in the outcome of the case.
These are ad hominem criticisms -- criticisms directed
"against the man" himself -- but there is no fallacy
involved, because the credibility of the man himself
is precisely what is at issue.
Or suppose that what is at issue is, again, not whether
a certain claim is true or a certain argument cogent,
but instead whether a certain person is reasonable,
intellectually honest, worth trying to have a conversation
For example, suppose someone in a combox shows himself
by his pattern of behavior to be an ignoramus, a crank,
a troll, etc. -- say by repeatedly making sweeping,
ungrounded, or unhinged assertions, dismissing ideas
and arguments he evidently does not even understand or
books he hasn't bothered to read, or indeed by committing
ad hominem and other fallacies right and left.
There is in such a case nothing wrong with calling such
a person an ignoramus, a crank, a troll, etc. and refusing
to engage with him any further.
That is certainly an attack on the person, but it is no
It is just a straightforward inference from the facts,
a well-founded judgment about him and his behavior,
rather than a fallacious response to some argument he
Or suppose someone gains a reputation for expertise on
some important matter of public controversy when in
fact his views about the matter are laughably off-base
and demonstrably ill-informed.
Suppose further that he manifests extreme arrogance and dismissiveness toward those who actually do have
expertise on the matter, where the fact of his unjustified self-confidence only serves to reinforce, in those who
don't know any better, the false impression that he must
know what he is talking about.
Here too an attack on the person himself is legitimate
precisely because what is at issue is one of his personal
qualities, viz. his arrogant pretense of expertise.
Indeed, ridicule and other polemical methods can be
legitimate tools in such an attack, since arrogant
pretense can often effectively be countered in no
other way, and treating the offender more gently might
only reinforce the false impression that he and his
views are respectable.
Hence it is, for example, not only legitimate, but in
my view imperative, not only to refute the sophistries
of smug hacks like Richard Dawkins and Lawrence Krauss,
but to administer a severe rhetorical beating as one
[ Here I must digress to address a pet peeve.
Something called "Feser's tone" is the subject of
occasional handwringing, not only among some of my
secularist critics, but also among a handful of
bed-wetters in the Christian blogosphere.
But there is no such thing as "Feser's tone," if that
is meant to refer to some vituperative modus operandi
Sometimes my writing is polemical; usually it is not.
I have written five books and edited two others.
Exactly one of them -- The Last Superstition -- is
Of course, some of my non-academic articles and blog
posts are also polemical. But that is an approach I
take only to a certain category of opponent, and
typically toward people who have themselves been
polemical and are merely getting a well-earned taste
of their own medicine.
Complaining about this is like complaining about
police who shoot back at bank robbers.
I've addressed the question of why and under what
circumstances polemics are justified in this post
and in other posts you'll find linked to within it.
End of digression. ]
The tu quoque is a species of ad hominem fallacy in
which a claim is rejected merely because the person
advancing it does not act in a way consistent with it.
But there are cases where the fact that a person's
actions are inconsistent with the claim he is making
is clearly relevant to evaluating the claim.
Suppose, for instance, that someone asserts that it
is not possible to make assertions.
This is a performative self-contradiction, and while
the probative value of identifying performative
self-contradictions is a matter of philosophical
controversy, it is legitimate at least to wonder
whether a view that entails such a contradiction
If someone could carry out a certain course of action
that he recommends to others but does not bother even
to try to do so himself -- the lush who condemns
others for their drinking, say -- that by itself
obviously does not show that his advice is not good
Mere hypocrisy is not of much epistemological interest.
But if there is reason to think that someone could not
even in principle adopt a certain policy, then it is at
least questionable whether the policy is a good one, or
reflects a coherent train of thought.
Finally, there are certain positions the very entertaining
of which cannot plausibly fail to reflect some degree of
moral defect in the person who advances them.
For moral character involves, in part, the having of
morally upright sensibilities, and these sensibilities
will tend to lead a person to regard certain actions as
beyond the pale and unworthy of serious consideration.
Hence that a given person does not so regard them is
evidence of defective sensibilities.
Suppose, for example, that someone seriously suggested
that there are good arguments in defense of torturing
babies "for fun."
It is hard to see how someone could sincerely believe
such a thing unless his moral sensibilities were deeply
(Whether he is culpable for this corruption is a question
I leave to one side as irrelevant to the present point.)
Notice what I am not saying.
I am not saying that "You are a bad person; therefore
your argument is invalid!" is a good response.
It is not a good response; that would be an ad hominem
If the practices a person is defending really are
immoral, there should be independent reasons, having
nothing to do with his personal character, that show
that they are.
All the same, if they are immoral, and if moral character
is in part a matter of having the right sensibilities,
and if a person shows by what he is willing to regard
as a live option that he does not have the right
sensibilities, then there is no fallacy in pointing this
Indeed, not to point it out might in some cases threaten
to undermine the moral sensibilities that prevail in society
at large, insofar as it might make certain immoral actions
seem respectable or defensible.
(For more on this issue, see my discussion of Elizabeth
Anscombe's views on the subject in an earlier post.)
There are at least five sorts of case, then, in which
criticism "of the man" can be legitimate and certainly
not fallacious, even when the larger context is one in which arguments are being weighed:
when determining whether someone's
testimony is likely to be reliable;
when evaluating his worthiness as a
philosophical conversation partner;
when exposing the fraudulence of his
public reputation for expertise on
when exposing performative self-
contradictions associated with some
philosophical position; and
when noting that a person's willingness
to take certain views seriously is
evidence of a corruption of his moral
None of this shows that a person's claims or arguments
themselves are undermined merely by calling attention
to his personal defects.
To suppose that it does would be fallacious.
But those who shout "Ad hominem!" too often do not know what
an ad hominem fallacy actually is.