Common Fallacies in Reasoning
Philosophy 150, Spring 1977
Prof. Kielkopf,
The Ohio State University
By Stephen M Golden, Copyright © 17 September 2014
I. False or Inaccurate
Assumptions:
III. Taken in by a Question’s Complexity:
IV. Begging the Question (petitio principii).
A. The
Appeal to Force (ad baculum): If the falsity of a proposition would make
me
suffer; it is not false.
{It will
be too bad for me if not-P. Therefore, P is true.}
B. The
Appeal to Pity (ad misericordiam): If the falsity of a proposition would make
another party suffer, it is not false.
{It
would be too bad for so-and-so if not-P. Therefore, P is true.}
C. The
Genetic Fallacy (ad hominem abusive): What a bad person says is false.
{X says
P, and X is a bad person. Therefore, P is not true.}
D. The
Circumstantial Fallacy (ad himinem circumstatial): If X asserts proposition P and it is in X’s
interest that P be true, then P is not true.
{X says
P. X would benefit by P being true. Therefore, P is not true.}
{X says
P. We can predict that someone in X’s position would say P.
Therefore,
P is not true.}
{X says
P. P is inconsistent with what X says elsewhere. Therefore, P is not true.}
{X says
P. P is inconsistent with X’s practice. Therefore, P is not true.}
E. The
Appeal to Ignorance (ad ignoratium): If a proposition
has not been shown to be false, it is true.
{P has
not been proven false. Therefore, P is true.}
F. The
Appeal to Popular belief (ad populum): If a proposition is believed by a vast
majority of people, it is true.
{Many,
many people say that P is true. Therefore, P is true.}
A.
Reliance on cliche’s: “Truth lies in the middle.” “Haste makes waste.” “All
people are created equal.” “Justice will triumph in the end.”
B. Fixed
ideas: “The U.S. cannot have another great depression.”
“Environmental
purity can be attained without great cost; it only requires goodwill.”
C.
Stereotypes of groups: “All of his kind of people are lazy.” “We could never
win a land war in Asia because “Asiatics” do not care
about their lives and they will let us kill them at a
ratio of 10 to 1 until we’re all gone.”
E.g.,
Why don’t people who favor legalized abortion think that the unborn have any
rights?
It can
easily be seen that there is more than one assertion being presented that has
not been
proven.
A. A
question is answered with a near synonymous statement of what is asked.
E.g., Q:
Why do you say I failed? A: You didn’t measure up to minimum performance
levels.
B. A
statement is made as though a claim which is yet to be proven has been proven.
E.g.,
“The bond issue has to be passed to provide new jobs.” The presupposition here
is that the question, “Will the bond issue provide new jobs” has already been
asked, and answered affirmatively.
E.g.,
“Christmas displays on city, state, or federally owned property (Including
school grounds) violate the constitutional guarantee of
church-state
separation” presupposes the question “Does the constitution guarantee
church-state separation?” in the affirmative.
C. The
justification for a premise is the conclusion.
E.g.,
“Suicide is wrong. I’ll tell you why it’s wrong. It is wrong because it is
against human nature. Now even if people do kill themselves,
we can
still say that suicide is against human nature because ‘nature’ can be used in
a normative sense. We do not have to mean
by
‘nature’ whatever happens in nature. In the normative sense ‘to be against
nature’ means to be contrary to what that thing ought to do. Thus, since humans
ought not to kill themselves, suicide is unnatural.”
A.
Considering a claim, suggestion, or argument only as a candidate for criticism,
not as a possible candidate for acceptance.
For
example: If someone criticizes our moral behavior, we shift the topic to the
difficulties of supporting any moral claim.
We could
also:
1. Pay
attention to the form of the message when the content counts.
E.g.,
criticize the grammar of an unfavorable evaluation.
2. Pay
attention to the content when the form counts.
E.g.,
defense of bad art because it has a good message.
3. Raise
a practical problem when a theoretical issue is in question.
E.g.,
raise questions about how a theory may be taught when the issue is the truth of
the theory.
4. Raise
theoretical issues when a practical question is at issue.
B.
Substitute acceptable reasons for our actions when in fact, we had poor reasons
for acting.
1. What I
failed to attain was not good; so my failure was not bad.
2. My
bad result has these compensating features; so, my choice was not
too bad.