FALLACIES
A _Fallacy_ is: "An unsound argument or mode of arguing, which, while
appearing to be decisive of a question, is in reality not so; an
argument or proposition apparently sound, but really fallacious; a
fallacious statement or proposition, in which the error is not apparent,
and which is therefore likely to mislead or deceive; sophistry."
In Deductive Reasoning, we meet with two classes of Fallacies; namely,
(1) Fallacious Premise; and (2) Fallacious Conclusion. We shall now
consider each of these in turn.
_Fallacious Premise_ is in effect _an unwarranted assumption of
premises_. One of the most common forms of this kind of Fallacy is known
as "_Begging the Question_," the principle of which is the assumption of
a fundamental premise which is not conceded; the unwarrantable
assumption of that which is to be proved; or the assumption of that by
which it is to be proved, without proving it. Its most common form is
that of boldly stating some unproven fact, authoritatively and
positively, and then proceeding to use the statement as the major
premise of the argument, proceeding logically from that point. The
hearer perceiving the argument proceeding logically often fails to
remember that _the premise has been merely assumed_, without warrant and
without proof and omitting the hypothetical "_if_." One may proceed to
argue logically from the premise that "The moon is made of green
cheese," but the whole argument is invalid and fallacious because of the
fact that the person making it has "begged the question" upon an
unwarranted premise. Hyslop gives a good example of this form of fallacy
in the case of the proposition "Church and State should be united."
Proof being demanded the advocate proceeds to "beg the question" as
follows: "Good institutions should be united; Church and State are good
institutions; therefore, Church and State should be united." The
proposition that "Good institutions should be united" is fallacious,
being merely assumed and not proven. The proposition sounds reasonable,
and few will feel disposed to dispute it at first, but a little
consideration will show that while _some_ good institutions may well be
united, it is _not_ a general truth that _all_ should be so.
"Begging the Question" also often arises from _giving a name to a
thing_, and then assuming that we have _explained_ the thing. This is a
very frequent practice with many people--they try to _explain_ by merely
applying names. An example of this kind is had in the case of the person
who tried to explain why one could see through a pane of glass by saying
"because it is transparent." Or when one explains that the reason a
certain substance breaks easily is "because it is brittle." Moliere
makes the father of a dumb girl ask why his daughter is dumb. The
physician answers: "Nothing is more easy than to explain it; it comes
from her having lost the power of speech." "Yes, yes," objects the
father, "but the cause, if you please, why she has lost the power of
speech." The physician gravely replies: "All our best authors will tell
you that it is the impeding of the action of the tongue."
Jevons says: "The most frequent way, perhaps, in which we commit this
kind of fallacy is to employ names which imply that we disapprove of
something, and then argue that because it is such and such, it must be
condemned. When two sportsmen fall out in some manner relating to the
subject of game, one will, in all probability, argue that the act of the
other was 'unsportsmanlike,' and therefore should not have been done.
Here is to all appearance a correct syllogism:
"No unsportsmanlike act should be done; John Robinson's act was
unsportsmanlike: Therefore, John Robinson's act should not have been
done.
"This is quite correct in form; but it is evidently the mere semblance
of an argument. 'Unsportsmanlike' means _what a sportsman should not
do_. The point to be argued was whether the act fell within the
customary definition of _what was unsportsmanlike_."
Arising from "Begging the Question," and in fact a class of the latter,
is what is called "Reasoning in a Circle." In this form of fallacy one
assumes as proof of a proposition the proposition itself; or, uses the
conclusion to prove the premise. For instance: "This man is a rascal
because he is a rogue; and he is a rogue because he is a rascal." Or,
"It is warm because it is summer; and it is summer because it is warm."
Or "He never drinks to excess, because he is never intemperate in
drinking."
Brooks says: "Thus to argue that a party is good because it advocates
good measures, and that certain measures are good because they are
advocated by so excellent a party, is to reason in a circle. So when
persons argue that their church is the true one, because it was
established by God, and then argue that since it is the true church it
must have been founded by God, they fall into this fallacy. To argue
that 'the will is determined by the strongest motive' and to define the
strongest motive as 'that which influences the will,' is to revolve in a
circle of thought and prove nothing. Plato commits this error when he
argues the immortality of the soul from its simplicity, and afterwards
attempts to prove its simplicity from its immortality." It needs care to
avoid this error, for it is surprising how easily one falls into it.
Hyslop says: "The fallacy of Reasoning in a Circle occurs mostly in
long arguments where it can be committed without ready detection....
When it occurs in a long discourse it may be committed without easy
discovery. It is likely to be occasioned by the use of synonyms which
are taken to express more than the conception involved when they do
not." What is called a Vicious Circle is caused when the conclusion of
one syllogism is used for a proposition in another syllogism, which in
its turn comes to be used as a basis for the first or _original
syllogism_.
_Fallacious Conclusion_ is in effect _an unwarranted or irrelevant
assumption of a logical conclusion_. There are many forms of this
fallacy among which are the following:
_Shifting ground_, which consists in the pretence of proving one thing
while in reality merely a similar or related thing is being proved. In
this class is the argument that because a man is profane he must
necessarily be dishonest; or that because a man denies the inspiration
of the Scriptures he must be an atheist.
_Fallacious Questioning_, in which two or more related questions are
asked, and the answer of one is then applied to the other. For
instance: "You assert that the more civilized a community, the more
silk-hats are to be found in it?" "Yes." "Then, you state that silk-hats
are the promoters and cause of civilization in a community?" A question
of this kind is often so arranged that an answer either in the
affirmative or the negative will lead to a false or fallacious
inference. For instance, the question once asked a respectable citizen
on the witness stand: "Have you stopped beating your mother?" An answer
of either "Yes" or "No," was out of the question, for it would have
placed the witness in a false position, for he had never beaten his
mother, nor been accused of the same.
_Partial Proof_, in which the proof of a partial or related fact is used
to infer a proof of the whole fact or a related one. For instance, it is
fallacious to argue that a man has been guilty of drunkenness by merely
proving that he was seen entering a saloon.
_Appeal to Public Opinion_, in which the prejudices of the public are
appealed to rather than its judgment or reason. In politics and
theological argument this fallacy is frequent. It is no argument, and is
reprehensible.
_Appeal to Authority, or Reverence_, in which the reverence and respect
of the public for certain persons is used to influence their feelings in
place of their judgment or reason. For instance: "Washington thought
so-and-so, and therefore it must be right;" or "It is foolish to affirm
that Aristotle erred;" or "It has been believed by men for two thousand
years, that, etc;" or "What our fathers believed must be true." Appeals
of this kind may have their proper place, but they are fallacies
nevertheless, and not real argument.
_Appeal to Profession_, in which an appeal is made to practices,
principles or professions of the opponent, rather than to reason or
judgment. Thus we may argue that a certain philosophy or religion cannot
be sound or good, because certain people who hold it are not consistent,
or not worthy, moral or sober. This argument is often used effectively
against an opponent, and is valid against him personally. But it is no
valid argument against his philosophy or belief, because he may act in
violation of them, or he may change his practices and still adhere to
his beliefs--the two are not joined.
_Appeal to General Belief_, in which an appeal is made to general or
universal belief, although the same may be unsupported by proof. This is
quite common, but is no real argument. The common opinion may be
erroneous, as history proves. A few centuries ago this argument could
have been used in favor of the earth being flat, etc. A half-century ago
it was used against Darwin. Today it is being used against other new
ideas. It is a fallacy by its very nature.
_Appeal to Ignorance_, in which an appeal is made to the ignorance of
the opponent that his conviction may follow from his inability to prove
the contrary. It is virtually no argument that: "So-and-so must be true,
_because you cannot prove that it is not_." As Brooks says: "To argue
that there is no material world, because we cannot explain how the mind
knows it to exist, is the celebrated fallacy of Hume in philosophy. The
fact that we cannot find a needle in a haystack is no proof that it is
not there."
_Introduction of New Matter_, also called _Non Sequitur_, in which
matter is introduced into the conclusion that is not in the premises.
Hyslop gives the following example of it: "All men are _rational_;
Socrates is a man; therefore, Socrates is _noble_." De Morgan gives the
following more complex example: "Episcopacy is of Scripture origin; The
Church of England is the only Episcopal church in England; therefore,
the church established is the church that ought to be supported."
Other fallacies, resembling in some respects those above mentioned, are
as follows:
_Fallacy of Ambiguous Terms_, in which different meanings of the same
word are used to produce the fallacious argument. As Jevons says: "A
word with two distinct meanings _is really two words_."
_Confusion between Collective and General Meanings of a Term_, of which
Jevons says: "It would be obviously absurd to argue that because _all_
the books in the British Museum Library are sure to give information
about King Alfred, therefore any particular book will be sure to give
it. By '_all_ the books in the British Museum Library,' we mean all
_taken together_. There are many other cases where the confusion is not
so evident, and where great numbers of people are unable to see the
exact difference."
_Arguing from the Collective to the General_, in which the fallacy
consists of arguing that because something is true of the whole of a
group of things, therefore it is true of any of those things. Jevons
says: "_All_ the soldiers in a regiment may be able to capture a town,
but it is absurd to suppose that therefore _every_ soldier in the
regiment could capture the town single handed. White sheep eat a great
deal more than black sheep; but that is because there are so many more
of them."
_Uncertain Meaning of a Sentence_, from which confusion arises and
fallacious argument may spring. Jevons says: "There is a humorous way of
proving that a cat must have three tails: Because a cat has one tail
more than _no_ cat; and _no cat_ has two tails; therefore, _any_ cat has
three tails." Here the fallacy rests upon a _punning_ interpretation of
"no."
_Proving the Wrong Conclusion_, in which the attempt to confuse
conclusions is made, with the result that some people will imagine that
the case is established. Jevons says: "This was the device of the
Irishman, who was charged with theft on the evidence of three witnesses,
who had seen him do it; he proposed to call _thirty_ witnesses who had
_not_ seen him do it. Equally logical was the defense of the man who was
called a materialist, and who replied, 'I am not a materialist; I am a
barber.'"
_Fallacy of Unsuccessful Argument_, in which is attempted the illogical
conclusion that _because a certain argument has failed the opposite
conclusion is proven_. This fallacy is quite common, especially in cases
of juries. One side fails to prove certain contentions, and the jury
leaps to the conclusion that the opposite contention must be correct.
This is clearly fallacious, for there is always the possibility of a
_third_ explanation. In the case of a claim of _alibi_ juries are apt to
fall into this fallacy. The failure of the attempt to establish an
_alibi_ is often held to be in the nature of proof of the guilt of the
accused. Old trial lawyers assert that a failure to establish a claimed
_alibi_ tends to injure the chance of the accused more than direct
evidence against him. Yet, as all logical reasoners will see, there is
no logical validity in any such inference. As Jevons has well said: "_No
number of failures in attempting to prove a proposition really disprove
it_." At the end of each failure the case simply stands in the same
position as before the attempt; _i.e._, "not proven."
_All Violations of the Rules of the Syllogism_ constitute fallacies, as
may be seen by forming a syllogism in violation of one or more of the
rules.
The logicians, particularly those of ancient times, took great pains to
discover and _name_ new variations of fallacies, many of which were
hair-splitting in nature, and not worthy of being considered seriously.
Some of those which we have enumerated may possibly be open to the same
criticism, but we have omitted many of the worst offenders against
practical common sense. An understanding of the fundamental Laws of
Reasoning is sufficient to expose and unmask all fallacies, and such
understanding is far more valuable than the memorizing of the _names_ of
hair-splitting fallacies which would not deceive a child.
In addition to the above stated fallacies of Deductive Reasoning, there
are other fallacies which are met with in _Inductive Reasoning_. Let us
briefly consider them.
_Hasty and False Generalization_ is a common fallacy of this class.
Persons sometimes see certain qualities in a few individuals of a class,
and mistakenly infer that _all_ the individuals in that class must
possess these same qualities. Travelers frequently commit this fallacy.
Englishmen visiting the United States for a few weeks have been known to
publish books upon their return home making the most ridiculous
generalizations regarding the American people, their assertions being
based upon the observation of a few scattered individuals, often not at
all representative. Americans traveling abroad commit similar errors. A
flying trip through a country does not afford the proper opportunity for
correct generalization. As Brooks says: "No hypothesis should be
accepted as true until the facts are so numerous that there can be no
doubt of its being proved."
_Fallacies of Observation_ result from incorrect methods of observation
among which may be mentioned the following: (1) _Careless Observation_,
or inexact perception and conception; (2) _Partial Observation_, in
which one observes only a part of the thing or fact, omitting the
remainder, and thus forming an incomplete and imperfect concept of the
thing or fact; (3) _Neglect of Exceptions and Contradictory Facts_, in
which the exceptions and contradictory facts are ignored, thereby giving
undue importance to the observed facts; (4) _Assumption of Facts_ which
are not real facts, or the assumption of the truth of things which are
untrue; (5) _Confusing of Inferences with Facts_, which is most
unwarrantable.
_Fallacies of Mistaken Cause_ result from the assumption of a thing as a
cause, when it is not so, of which the following are familiar examples:
_Substituting the Antecedent for the Cause_, which consists in assuming
a mere antecedent thing for a _cause_ of another thing. Thus one might
assume that the crowing of the cock was the _cause_ of daybreak, because
it _preceded_ it; or that a comet was the cause of the plague which
followed its appearance; or in the actual case in which a child reasoned
that doctors _caused_ deaths, because observation had shown that they
always visited persons before they died; or that crops failed because a
President of a certain political party had been inaugurated a few months
before. Some fallacies of everyday reasoning are quite as illogical as
those just mentioned. _Substituting the Symptom for the Cause_, which
consists in assuming as a _cause_ some mere symptom, sign or incident of
the real cause. To assume that the pimples of measles were the _cause_
of the disease, would be to commit a fallacy of this kind. We have
mentioned elsewhere the fallacy which would assume silk-hats to be the
cause of Civilization, instead of being a mere incident of the latter.
Politicians are fond of assuming certain incidents or signs of a period,
as being the _causes_ of the prosperity, culture and advancement of the
period, or the reverse. One might argue, with equal force, that
automobiles were the causes of national prosperity, pointing to the fact
that the more automobiles to be seen the better the times. Or, that
straw hats produced hot weather, for similar reasons.
_The Fallacy of Analogy_ consists in assuming a resemblance or identity,
where none exists. We have spoken of this in another chapter. Brooks
says, also: "It is a fallacy to carry an analogy too far; as to infer
from the parable of the praying of the importunate woman that God
resembles the unjust judge."
In conclusion, we would call your attention to the following words from
Jevons, in which he expresses the gist of the matter: "It is impossible
too often to remind people that, on the one hand, _all correct reasoning
consists in substituting like things for like things_, and inferring
that what is true of one will be true of all which are similar to it in
the points of resemblance concerned in the matter. On the other hand,
_all incorrect reasoning consists in putting one thing for another where
there is not the requisite likeness_. It is the purpose of the rules of
deductive and inductive logic to enable us to judge as far as possible
when we are thus rightly or wrongly reasoning from some things to
others."
FINIS.
TRANSCRIBER'S NOTE:
Obvious typos and printer errors have been corrected without comment. In
addition to obvious errors, the following changes have been made:
Page 18: "Idea" changed to "Ideas" in the phrase, "... forming
Concepts or General Ideas."
Page 71: "infuoria" changed to "infusoria" in the phrase, "... the
microscopic infusoria...."
Page 135: "disciple" changed to "discipline" in the phrase, "...
necessity of discipline for invention...."
Other than the above changes, no attempt has been made to correct common
spelling, punctuation, grammar, etc. The author's usage is preserved as
printed in the original publication.