Considered below is the precise composition of argument ad hominem.  After that are some critiques of some modern scholars'  views in relation to argument ad hominem.  Next I describe a use of two definitions of this fallacy in a proposed law that would effectively counter this fallacy in trials, and, state the various benefits of this law.  Then I describe the overall significance of argument ad hominem, ask when the proposed law will be created, and note that the American government has an ethical duty, sooner or later, to create such a law.  Also noted is the need for psychological research into the persuasiveness of argument ad hominem.

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                                                         Precisely what is “argument ad hominem” ?

 

        Much has previously been written about argument ad hominem (also called argumentum ad hominem), but all of this writing is very limited, or wrong, or both, as viewed against an ad hominem fallacy I discovered.  This is shown in detail in the book, and sketched below.  What  I mean by an “ad hominem fallacy” is stated after the next paragraph.  The logical significance of the ad hominem fallacy I discovered is described in the next paragraph. 

 

        I searched for the composition of that ad hominem fallacy which is most broadly applicable to human ideas, because of: 1) the greater logical significance of this ad hominem fallacy compared to any narrower ad hominem fallacy (as any narrower ad hominem fallacy is included in the broadest ad hominem fallacy), and, 2) the greater logical significance of this ad hominem fallacy compared to any ad hominem form of argument that is not a fallacy but is merely generally illogical, not perfectly illogical.  Eventually I discovered the composition of that ad hominem fallacy which is most broadly applicable to human ideas (or so I believe).  This discovered fallacy happens to be very broadly applicable to human ideas.  The label "argument ad hominem" is pejorative in colloquial use, by suggesting that any argument that is an "argument ad hominem" is illogical.   This pejorative label, "argument ad hominem", I have re-applied to refer to that ad hominem fallacy which is most broadly applicable to human ideas.  To re-apply the label "argument ad hominem" to this fallacy is justified, because this broadest of all ad hominem fallacies has greater logical significance than any other candidate for the label "argument ad hominem", including the two other candidates stated in the first sentence of this paragraph.          

 

       To explain what I mean by an “ad hominem fallacy”, first I must state the basic meaning of “argument” that I use.  I use the word “argument” in its sense in logic, as opposed to meaning a disagreement.  In logic “argument” refers to a claim that some specified premiss or premisses support/s a specified conclusion.  (A much fuller definition of “argument”, in its sense in logic, is in the book.)

 

        Every argument has some particular "form" or other.  Each “form” of argument is like a unique shape, such as, a square, or a circle.  All individual square-shaped objects “take” that same shape, of a square, with four sides of equal length and four right angles.  Although there can be an infinity of square-shaped objects, there is only one square shape.  Each form of argument is unique.  And, with respect to each form of argument, an infinity of individual arguments can “take” its form.  (A definition of the “form” of an argument is in the book.)

 

    A “fallacy” is a form of argument that is a perfect non-sequitur, that is, all individual arguments of any fallacious form of argument are illogically reasoned.  Thus in every individual argument that takes the form of a fallacy, the premiss/es of that argument fail to support its conclusion, by irrelevance.

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      In every "ad hominem" fallacy: one premiss consists of an identified man’s alleged idea, a second premiss consists of some alleged attribute/s of his, in the conclusion only the worth of his alleged idea is judged, and, the premisses provide no logical support for the conclusion, that is, the premisses are irrelevant to the conclusion.  By a "man" in the preceding sentence, and in the next paragraph, is meant any person, regardless of gender or age.

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        I searched for the composition of that ad hominem fallacy which is most broadly applicable in judging a man’s ideas, and discovered its composition, after many years of reflection (unless I overlooked an even broader such fallacy, despite a rigorous effort to avoid this possibility).  This ad hominem fallacy is very broadly applicable in judging a man’s ideas. 

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     In the book the oft-used label “argument ad hominem” is rightly re-applied, to this broadest of all ad hominem fallacies, because, to apply that label to anything narrower is to omit, under that label, at least one existing species or other of ad hominem fallacy.  I also call argument ad hominem synonymously “the mega fallacy”, because of its vast breadth of applicability to a man’s ideas.

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       My description of the composition of argument ad hominem is the only description of an ad hominem fallacy that is per genus et differentiam.  The book explains in precise detail: what all arguments ad hominem have in common (the genus), and, what distinguishes the species of this genus (the differentiam).  Each individual argument ad hominem belongs to some species or other of this genus, like each individual rat belongs to some species or other of the genus Rattus.  The ancient Greeks recognized just three species of ad hominem fallacy.  I discovered there are forty eight “basic” species (which include the Greeks’ three species), and there are countless more complex species.     

 

       The full definition of argument ad hominem, which is stated only in The Solution to an Injustice in Trials, is about 140 pages long, such is the complexity of this fallacy.  But stated next is a one-page functionally equivalent definition, quoted from the book.

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                                         "The functionally equivalent definition of argument ad hominem

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     The form of argument ad hominem is described in Part II, and is long and complex.  But there is a far shorter definition of “argument ad hominem” that is a functional equivalent.  Stated next is the functionally equivalent definition of argument ad hominem, to provide an immediate functional understanding. 

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     An argument ad hominem is any illogical argument that:

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1) rejects a man’s idea based on irrelevant criticism of him (be his cited attribute/s in the argument objectively critical of him and/or presented or implied as critical of him in the argument), or,

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2) upholds a man’s idea based on irrelevant praise of him (be his cited attribute/s in the argument objectively praise of him and/or presented or implied as praise of him in the argument), or,

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3) rejects a man’s idea based on an inconsistency between: i) some attribute/s of his (cited in the argument) and ii) his idea, provided the inconsistency reflects negatively on him, and/or the inconsistency is presented or implied in the argument as critical of him, or,

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4) rejects a man’s idea based on both: a) irrelevant criticism of him (be his cited attribute/s in the argument objectively critical of him and/or presented or implied as critical of him in the argument), and, b) an inconsistency between: i) some attribute/s of his (cited in the argument) and ii) his idea, provided the inconsistency reflects negatively on him, and/or the inconsistency is presented or implied in the argument as critical of him.

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     In this definition the following terms have the following meanings:

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a) an “argument” means a claim (implicit or explicit) that some specified statement/s happen/s to support another specified statement as being any of: true, or, probably true, or, true or probably true, but not as being necessarily/unavoidably true, even if the allegedly supporting statement/s is/are true.  Explanation: a claim of a necessarily/unavoidably true conclusion can be made in deductive logic, but not in inductive logic, and argument ad hominem is inductive, not deductive.  Deduction and induction are different sorts of logic;    

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b) an “illogical” argument means the conclusion of the argument is not supported, as a matter of reasoning, by whatever material in the argument allegedly supports the conclusion.  Assume that the allegedly supporting material in an argument is true.  If that material (assumed to be true) does not support the conclusion of the argument, then the argument is illogical;

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c) “man” means any identified person, regardless of gender or age;

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d) “a man’s idea” and “his idea” both mean a specified idea of a man, or, a specified idea allegedly of his;

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e) a man’s “attribute” means an alleged attribute of his, whether he actually has that attribute or not."

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         Here is an example of the first sort of argument ad hominem numbered above.  “John asserts the earth is round, but John is revolting, so the earth is not round.”  This argument ad hominem rejects a man’s idea based on irrelevant criticism of him.  John being revolting is irrelevant to whether or not the earth is round, making this argument illogical.  

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      Importantly, in some exceptional sorts of circumstances, a man is relevant to the worth of his idea.  But nobody has identified all of these exceptional sorts of circumstances.  In The Solution to an Injustice in Trials there is a list of some of these exceptional sorts of circumstances: all those that exist within a specified ad hominem context, which context is defined in the book, and is called "the candidate context".  The candidate context, with the list of exceptional sorts of circumstances, provide the basis for a complete set of “exclusions”, such that the form I claim is the broadest ad hominem fallacy that exists, qualifies as a fallacy, rather than merely being a generally illogical form.  The respective compositions of the exclusions are all complex, and are specified in detail in the book.

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     Thus, to know fully what argument ad hominem is, you will either have to read its unavoidably lengthy description in The Solution to an Injustice in Trials, or, discover its full composition for yourself.  Its full composition is the full composition of the broadest ad hominem fallacy that exists, as only this fallacy is rightly labeled "argument ad hominem", because this fallacy has greater logical significance than any other candidate for the label "argument ad hominem", including: 1) any narrower ad hominem fallacy, and, 2) any merely generally illogical form of ad hominem argument.   (Again, although I claim to have discovered the full composition of the broadest ad hominem fallacy that exists,  I might conceivably be mistaken, as there might - unimaginable to me - be an even broader ad hominem fallacy than the one I discovered, in which case, if it were found, it would rightly be called argument ad hominem.  This abstract possibility of error is hereafter ignored/not repeated in the rest of this web page, apart from in a disclaimer stated further below.)

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                               Some modern errors regarding the composition of argument ad hominem

 

       Some modern writers (cited in the book) corrupt the notion of a "fallacy" by allowing a fallacy to be a merely generally illogical form, as opposed to a "fallacy" being a perfect non-sequitur.  These writers thereby call argument ad hominem a fallacy while asserting that there are exceptions to argument ad hominem being illogical.  But these writers neither provide a complete list of these exceptions nor claim to provide a complete list of these exceptions.  In contrast, with the aid of the complete set of "exclusions" noted above (and specified in the book), the composition of the broadest ad hominem fallacy that exists is now known, with a “fallacy” here meaning a perfect non-sequitur.  The broadest ad hominem fallacy that exists is very broadly applicable to a man's ideas, as shown in the book.  To know the composition of this very broad fallacy is more valuable than to know the composition of any merely generally illogical ad hominem form of argument. Thus the label "argument ad hominem" is rightly re-applied to refer to the broadest ad hominem fallacy that exists, not to any narrower ad hominem fallacy, nor to any merely generally illogical form of argument.

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      A common modern error (cited in the book) is to include impeachment of a man's credibility under the label "argument ad hominem".  Judging a man's credibility is an importantly different topic from judging the worth of a man's idea.  To place both topics under the same label, argument ad hominem, is pointless.  Moreover, this dual treatment of what constitutes "argument ad hominem", makes this label, as so treated, fail to stand for a fallacy.  This failure is because various attributes of a man are relevant to his credibility, such as his bias, interest, or other motive.  The only topic in the conclusion of "argument ad hominem", where this label stands for an ad hominem fallacy, is a judgment of the worth of the man's idea alleged in the argument.  This is the only topic in the conclusion in both the full definition of argument ad hominem (in the book), and, in the conclusion in the functionally equivalent definition (quoted above).   

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A quite detailed critique of a modern scholar’s description of argument ad hominem, to illustrate further that modern scholars do not understand the fallacy of argument ad hominem

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     The following quote is from The History of Philosophy, at pages 594-595, by Prof. A.C. Grayling (Penguin 2019).  Professor Grayling (1949 - ) is a modern scholar, Master of the New College of the Humanities (in London), and a Supernumerary Fellow of St. Anne’s College, Oxford University.

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“A very common form of fallacy is the ad hominem argument, which is an attack on a person rather than on his or her argument.  It takes different forms; there can be direct abuse of an individual, insinuations and hints that associate the individual with bad people or happenings, ridicule of the individual and redounding a charge on the individual (‘you too’, tu quoque).” 

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     The above-quoted paragraph is Grayling’s entire description of argument ad hominem in his book.

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     The first phrase in the above quote, “A very common form of fallacy is the ad hominem argument”, is correct, but, his description of the composition of argument ad hominem is incorrect, as shown below.

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   The second phrase in the above quote incorrectly asserts that ad hominem argument “is an attack on a person rather than on his or her argument”.  This quote, his sole  description of the composition of argument ad hominem, has major errors and even bigger omissions.

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     First, argument ad hominem is not a physical attack, but Grayling’s above phrase does not exclude that sort of attack.  John argues to a burglar that the burglar should leave his home immediately because John has already called the police.  The burglar punches John in the face.  This punch is a physical attack on John, not an attack on John’s argument, but this physical attack fits the description of ad hominem argument in Grayling’s second phrase.  Clearly that phrase is too broad in its meaning, by including a physical attack, but this error is amended next.

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     Second, ad hominem argument is not even a verbal “attack on a person rather than on his or her argument”.   A mere verbal attack on John, such as by the burglar saying to John “you stink”, is not an argument, nor an argument ad hominem, just personal criticism.  And mere personal criticism is not a fallacy, because a fallacy is an invariably illogical form of argument, and mere personal criticism is not any form of argument.  Grayling’s (amended) version of argument ad hominem, i.e. mere personal criticism, is not a fallacy, but, he inconsistently (yet correctly) describes ad hominem argument as a fallacy. 

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    Third, in argument ad hominem, the arguer ad hominem does address the targeted man’s idea, and the targeted man’s idea may be either an argument in its sense in logic, or, his idea may be several other sorts of idea, including factual assertions and assertions of probable fact.  All of the sorts of idea of a man that can be addressed in argument ad hominem are implied in The Solution to an Injustice in Trials.  These sorts of idea are implied in Part II of the book, under its “Commonality 6” sub-heading, which Commonality concerns which criteria of the worth of an idea can be used in the conclusion of argument ad hominem.

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     In the above fact-pattern John is the targeted man, and his idea is an argument: his argument as to why the burglar should leave immediately.  If the burglar rejects John’s argument by saying it is a bad argument, because John stinks, that is an argument ad hominem.

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     So what led Grayling to describe argument ad hominem incorrectly as “an attack on a person rather than on his or her argument” ?  And why is this incorrect view shared by some other modern scholars ?

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    The explanation may be a too literal reading of Aristotle’s words: “these persons [various debaters] direct their solutions against the man, not against his argument.”  Sophistical Refutations, Chapter 22, 178b at lines 17-18, translated by W. A. Pickard, Cambridge, repeated in “The Complete Works of Aristotle” Princeton University Press (1995), Vol. 1, at page 304.

 

     Aristotle’s above-quoted words should not be read literally to mean that “their solutions” are just personal criticism of a speaker.  Mere personal criticism is not an argument in its sense in logic, because mere personal criticism makes no claim that some specified premiss or premisses support/s a specified conclusion. So while mere personal criticism might be false and/or distracting it cannot be illogical; it cannot be a non-sequitur.  Mere personal criticism has no logical significance, and, the possibility of personal criticism in discourse is obvious, being very common in society. 

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      Aristotle was a genius, the world’s first great logician, and, his above-quoted words appear in his Sophistical Refutations, which is a book about some fallacies in logic.  Thus Aristotle’s above-quoted words are better understood to have the following meaning, which is relevant to logic: the debaters make an illogical argument that rejects the man’s argument, their argument being based on their personal criticism of him.  In other words, Aristotle’s “not against his argument” should be read to mean: “not logically against his argument, but rather illogically against his argument, based on personal criticism of him.”  The debaters’ illogical argument, based on personal criticism of a targeted man, is an argument in its sense in logic, and, being such an argument, does have logical significance: it is illogical, a non-sequitur. 

 

    Also, under another too literal reading of Aristotle's above-quoted words, these words can be interpreted to refer merely to an argument in which: the debaters only aim to impeach the speaker's credibility based on personal criticism of the speaker, and, the debaters do not address the worth of the speaker's argument.  Mere purported impeachment of a speaker's credibility may or may not be logical, depending on its basis.  Because some impeachment of a speaker is logical, e.g. based on a speaker's bias, mere impeachment of a speaker's credibility is not a fallacy, as a fallacy is an invariably illogical form of argument.  Logical mere impeachment of a speaker's credibility only proves that the speaker's word for his idea is unreliable (assuming the invoked personal criticism of him is true), and so mere impeachment of the speaker leaves open whether the speaker's argument has merit.  Thus mere impeachment of a speaker's credibility is not a fallacy (as sometimes logical) and so such impeachment is not what Aristotle had in mind in his above-quoted words from his Sophistical Refutations, which is a book about some fallacies.

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    An unreflective mentality towards Aristotle's writings, due to excessive reverence for Aristotle, has been common for centuries, and may have caused some modern scholars to read Aristotle's above-quoted words too literally, in the two above-stated ways.  Bertrand Russell (1872-1970) noted:  "Throughout modern times, practically every advance in science, logic, or in philosophy has had to be made in the teeth of the opposition from Aristotle's disciples."  A History of Western Philosophy, Book One, Part II, Chapter XXII, titled Aristotle's Logic, final paragraph, 1945.

 

     Fourth, regardless of what Aristotle’s above-quoted words mean, the phrase “argument ad hominem” should, for greater logical significance, refer to a fallacy, in its sense in logic, not to impeachment of a speaker's credibility.  This is because a fallacy in its sense in logic, i.e. an invariably illogical form of argument, has, by this consistency, more logical significance than impeachment of a speaker's credibility, which is a form of argument that is only sometimes illogical, and thus is not a fallacy.  Moreover, the conclusion in the fallacy (of what is better labelled "argument ad hominem") addresses the worth of the targeted man's idea in question, which topic is more significant than - and fundamentally different from - merely impeaching the man's credibility as to his idea in question.   And, mere personal criticism (i.e. without using the personal criticism for impeachment) is not even an "argument" in its sense in logic, and has no logical significance, being neither logical nor illogical.   Thus to label mere personal criticism, or impeachment of a man's credibility, as "argument ad hominem", are clearly inferior uses of that label.

 

   Argument ad hominem is important because it is sometimes psychologically persuasive, and can deceive, despite being a fallacy/invariably illogical.  

 

     Mere personal criticism can distract from consideration of a criticized person’s idea, by changing the subject, but such distraction is not a fallacy in logic, not being an "argument" in its sense in logic.  The meaning of “argument” outside logic is a mere disagreement.  The only way for the word “argument” in the phrase “argument ad hominem” to make any clear sense, is by this word “argument” having its meaning in logic.  In contrast, substituting the non-logical meaning of argument, i.e. “a mere disagreement” for “argument” in the phrase “argument ad hominem”, yields the phrase “a mere disagreement ad hominem”, which phrase hardly makes sense, if at all.  The meaning, if there is one, is a mere disagreement related to a mere personal criticism, which is obscure by not specifying the sort of relationship asserted.  There is a relationship of some sort or other between any two things in the universe, even if merely that they co-exist in the same universe.   

 

     Fifth, Grayling’s description of argument ad hominem omits the composition of the genus of argument ad hominem, that is, what all arguments ad hominem have in common.  The genus is described, for the first time in any publication, in six “Commonalities” in The Solution to an Injustice in Trials.  These commonalities are six essential formative attributes that all arguments ad hominem have in common.  The genus, composed of these six attributes, exists, like there is a genus Rattus, with its 56 species of rats.  Next is an overview of the six Commonalities, quoted from The Solution to an Injustice in Trials.

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“If an argument satisfies all of Commonalities 1-6 then it is an argument ad hominem, but otherwise it is not an argument ad hominem.  If an argument uses a criterion of the worth of an idea that requires exclusions, the argument must not fall within an exclusion, in order for the argument to satisfy Commonality 6.  The exclusions are in the Appendix Section 1.2.

 

AN OVERVIEW OF COMMONALITIES 1-6

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For an overview, all 6 Commonalities are restated next, but without their footnotes or other amplifications (which appear above in Part II).

 

COMMONALITY 1) Premiss 1, an indicated man and a specified idea allegedly of his.

                                                                                                                                               

COMMONALITY 2) Premiss 2: some alleged attribute/s of the indicated man in Commonality 1, besides his alleged attributes in Commonality 1.

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COMMONALITY 3) A conclusion, judging only the worth of the man’s alleged idea in Premiss 1.

 

COMMONALITY 4) The man indicated in Commonality 1, as portrayed in the argument (in Premisses 2 and 1), and, the worth of his alleged idea, as judged in the conclusion, both have the same emotional resonance, both negative or both positive, e.g. a bad man’s idea is false (both negative), or a good man’s idea is true (both positive).

 

COMMONALITY 5) An implicit or explicit claim that any given argument in question is cogent and good.  Any given argument in question must be inductive, not deductive, to satisfy Commonality 5. 

 

COMMONALITY 6) Commonality 6 limits the criteria of the worth of an idea that can generally be used in the conclusion (Commonality 3) by which to judge the worth of the man’s idea in Premiss 1 (Commonality 1).  Only eleven criteria of the worth of an idea are generally permitted, but, using some of these criteria in the conclusion, is subject to exclusions, stated in the Appendix Section 1.2.  And, in certain circumstances (stated above in Part II under a sub-heading Shielding cogency in spurious conclusions), other criteria of the worth of an idea can also be used in the conclusion.  Commonality 6 is not satisfied with respect to any given argument in question if any exclusion (in the Appendix Section 1.2) applies to that argument.”

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       The respective meanings in Commonality 5 of the terms "cogent", "good", "inductive" and "deductive", are described in detail in The Solution to an Injustice in Trials, but these meanings are also outlined in my Blogs 2 and 3, which can be viewed by clicking here.

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     The "eleven criteria of the worth of an idea" referred to above in Commonality 6 are all specified in the full description of COMMONALITY 6, in Part II of The Solution to an Injustice in Trials.

 

     Sixth, Grayling’s description of argument ad hominem omits that there are four sub genera of argument ad hominem, not just one: 1) critical, 2) laudatory, 3) circumstantial, and 4) critical & circumstantial, all as described in The Solution to an Injustice in Trials.  For a basic understanding of each of the four sub-genera see points numbered 1-4, respectively, in the above-quoted functionally equivalent definition. 

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     All of what Grayling describes as “different forms” of argument ad hominem in his above-quoted paragraph, fall under only one sub genus: the critical sub genus.  All forms of personal criticism can be used in argument ad hominem, not just the forms of personal criticism that Grayling describes in his “different forms”.  Notably, there is overt non-abusive personal criticism, which falls outside Grayling’s “different forms”, such as calling a rightly convicted rapist “a convicted rapist”.  The first sub genus is better called “critical” rather than “abusive”.  “Abusive” is a narrower label (than “critical”) that some modern scholars use in relation to argument ad hominem.  The label “abusive” omits non-abusive personal criticism, yet, non-abusive personal criticism can nonetheless be used to argue ad hominem, like all forms of personal criticism.  One can argue ad hominem politely.

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    Seventh, Grayling’s description of argument ad hominem, by omitting the composition of the genus of argument ad hominem, and by omitting three of its four sub genera, and by only partly addressing the critical sub genus, also omits that there are: 1) forty eight basic species of argument ad hominem (not just three basic species the ancient Greeks discovered), and, 2) countless complex species.  The species are described in The Solution to an Injustice in Trials.

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     In sum, Grayling’s description of the composition of argument ad hominem is incorrect, and is very limited, by its major omissions.    

 

     To criticize the omissions in his description is to use the phrase “argument ad hominem” to stand for the ad hominem fallacy that is most broadly applicable to human ideas.  This use of the phrase "argument ad hominem" is logically superior to any use of the phrase “argument ad hominem” that stands for any narrower ad hominem fallacy.  This superiority is because the broadest ad hominem fallacy (composed of an entire genus, all its sub genera, and all its species) includes every narrower ad hominem fallacy (every sub genus and every species), and so the broadest ad hominem fallacy comprises more of logic than any narrower ad hominem fallacy.  Grayling presumably did not ask the logically most important question about the composition of argument ad hominem (i.e. What is the composition of the ad hominem fallacy that is most broadly applicable to human ideas ?), as that posited non-inquiry, if true, would explain why his description of argument ad hominem (a mere personal attack) is so far from describing the very broad composition of that fallacy.

 

     If “argument ad hominem” is used in a non-logical way, e.g. to stand for mere personal criticism, then it is not, under such use, a fallacy, nor therefore any ad hominem fallacy.  One can name anything non-logical “argument ad hominem”, such as one’s dog, but that does not make the named thing a fallacy, nor therefore an ad hominem fallacy.

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     In contrast, The Solution to an Injustice in Trials contains the most comprehensive and detailed description of the composition of argument ad hominem ever published, revealing this form of argument to be a far broader fallacy than was previously known.  This vast breadth is why argument ad hominem is also called “the mega fallacy” in The Solution to an Injustice in Trials.  Grayling’s description of the composition of argument ad hominem, as a mere personal attack, does not describe even a mini fallacy; it is not part of logic.

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   There is an overview diagram of argument ad hominem/the mega fallacy, in The Solution to an Injustice in Trials. This diagram is presented and discussed on You Tube, and is available at  https://www.youtube.com/watch?v=y76IfrCsO-U in a video titled "ARGUMENT AD HOMINEM - A FALLACY UNMASKED".  The diagram is at 26:20, near the end of the video.

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Another critique of a modern scholar’s description of argument ad hominem, to illustrate further that modern scholars do not understand the fallacy of argument ad hominem

 

    The following quote is from Rationality, at pages 90-91, by Prof. Steven Pinker (Penguin 2021).  Professor Pinker (1954 - ) is a modern scholar, the Johnstone Family Professor of Psychology at Harvard University, a member of the National Academy of Sciences, and one of Time’s “100 Most Influential People in the World Today”.

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     He describes argument ad hominem as: “the attempt to rebut an idea by insulting the character, motives, talents, values, or politics of the person who holds it.  The fallacy is called arguing ad hominem, against the person.  … Often the expression is more genteel but no less fallacious.  ‘We don’t have to take Smith’s argument seriously: he is a straight white male and teaches at a business school.’  ‘The only reason Jones argues that climate change is happening is that it gets her grants and fellowships and invitations to give TED talks.’”

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     The above quote suffers from all of the same omissions in points five, six, and seven of the above critique of the quote of Grayling, regarding the composition of argument ad hominem.  Pinker presumably did not ask the logically most important question about the composition of argument ad hominem (i.e. What is the composition of the ad hominem fallacy that is most broadly applicable to human ideas ?), as that posited non-inquiry, if true, would explain why his description of argument ad hominem is so far from describing the very broad composition of that fallacy.

 

     Pinker is correct that argument ad hominem is a “fallacy”, but his phrase “less fallacious” is misconceived, because fallaciousness does not come in degrees.  His phrase “less fallacious” is misconceived in the same way that “less triangular” is misconceived: by diluting an absolute.

 

      Pinker’s sentence featuring Jones, in the above quote from Rationality, is supposedly an argument ad hominem, but is not one.  Rather, that sentence is merely an example of impeachment by bias, which is not a fallacy.  Clearly Jones’ credibility is fairly impeached in that sentence (assuming she does stand to gain by making her climate argument), but that impeachment only shows she is an unreliable source for her argument (about climate change), and the sentence does not address the merits of Jones’ argument (about climate change).  Calling impeachment of a person’s credibility "argument ad hominem" is a common modern error, as noted above on this web page.  Argument ad hominem is a fallacy, but there is no fallacy in impeachment by bias, because a person being biased is relevant to her unreliability as a source for her idea.  The sole topic in the conclusion of argument ad hominem is not impeachment, but, rather, that sole topic is stated above, under the COMMONALITY 3 sub-heading, within the above critique of Grayling's version of argument ad hominem.

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A critique of a psychological study: “The effect of ad hominem attacks on the evaluation of claims promoted by scientists.”  Dr. Ralph Barnes et al, January 30, 2018, available at https://doi.org/10.1371/journal.pone.0192025

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     This psychological study, while interesting, is fundamentally flawed.  The participants in the study were required to choose from a range of six possible answers, but this range failed to include an important logically possible answer, indeed an answer that in some circumstances was the only logical answer. 

 

     A scientific claim of a hypothetical scientist was presented to the participants, and, in some questions, some impeaching information about the scientist who made the claim was added.  In other questions, evidence relevant to the scientist’s claim was added, or, both evidence relevant to the scientist’s claim and impeaching evidence about the scientist, was added, but neither of these two sorts of questions is considered much in this critique.    

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    All of the questions in the study required the participants to state their attitude towards whether or not the scientific claim was true, including the questions just with the additional impeaching information about the scientist. In the study there were six answer options for a participant to choose between to express his/her attitude to whether or not a scientific claim was true.  But in the study there was no answer option that a participant’s attitude towards whether or not the scientific claim was true, was unchanged by the mere addition of impeaching information about the scientist. 

 

     If a man is shown to be an unreliable source for a claim he makes, that impeachment of his credibility is not any logical basis for judging whether or not his claim is true.  In such circumstances one’s attitude to the merits of his claim can only, logically, be unchanged.  One does not rely on his word for his claim, his word being unreliable, but one does rationally consider other evidence of the claim, if there is any other evidence.  By the psychological study omitting as an answer option this neutral/unchanged attitude position, regarding the merits of the scientist’s claim, the study is fundamentally flawed.  Here are the study’s six answer options, quoted from the study:

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“Example issue: the cause of the common cold

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Claim A

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According to one source… The common cold is caused by a virus.

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According to another source… The common cold is caused by going outside in the winter with wet hair.

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Favor Claim A    1 2 3 4 5 6    Oppose Claim A

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In the example above you would circle a

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1 if you strongly favored the virus hypothesis

2 if you moderately favored the virus hypothesis

3 if you somewhat favored the virus hypothesis

4 if you somewhat opposed the virus hypothesis

5 if you moderately opposed the virus hypothesis

6 if you strongly opposed the virus hypothesis”  Article at “S2 File”.

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    The claim in the above example is “the virus hypothesis”.  There should, in the study’s answer options, be a neutral option, of neither favoring nor opposing the claim, which option would fall between numbered options 3 and 4 in the above range of options.  Often in life we lack sufficient data to reach a conclusion logically, other than “I don’t know enough to say, one way or the other”.  This is a logical possibility that is omitted from the study, and which makes it defective. 

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   Also, in the first of two experiments in the study, the participants were all psychology students, and were given “extra credit” for their participation.  So, they had a bias to pick one of the six available answer options, in order to get the “extra credit”, even if their real answer were “neutral/no attitude for or against”. 

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     Answers from 41 participants in the first experiment were discarded, 30 for failure to finish the questionnaire, and 11 for not following instructions.   The study does not address whether these participants’ thoughts about the study were investigated.  They may have refused to be shoe-horned into an illogical answer.  Clearly neutral/no change in attitude, was the only logical answer (in terms of attitude) where only impeachment of the scientist’s credibility was added to the scientist’s claim.

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     Those participants who indicated they had a negative attitude to the scientist’s claim, where the added material to the scientist’s claim was solely impeachment of the scientist, may, or may not, have opposed the scientist's claim by freely arguing ad hominem against the claim, based on the material impeaching the scientist's credibility.  Besides freely making that illogical inference they may have picked a negative attitude option for some other cause.  That other cause could be (for those in the first experiment) to get extra credit, without making any illogical inference.  Or, that other cause could be that a participant, without making any inference, was unduly influenced by the implied suggestion of the six answer options that some attitude, favoring or opposing/positive or negative - must be felt – that one cannot have no attitude/one cannot be neutral towards the scientist’s claim.  Or, that other cause could be that the above implied suggestion influenced a participant to argue ad hominem against the scientist's claim, based on the material impeaching the scientist's credibility.

 

     But just because this psychological study was flawed does not mean its results are false, including “that some strictly ad hominem attacks (specifically the conflict of interest and past misconduct attacks) are just as effective as attacks on the empirical foundation of a claim”.  Article at its page 9.  A properly constructed psychological study might reach the same result, which result, if true, would be a sad comment on human irrationality/gullibility.  The high degree of irrational opposition in the world towards safe and effective Covid-19 vaccines underscores the need for such psychological research, for the world’s health, and, for fair jury trials involving scientific claims.  The sooner the relevant psychological research is done, the better.

 

     Besides psychological research of the persuasiveness of argument ad hominem in the scientific context, also required is psychological research of the persuasiveness of argument ad hominem in the non-scientific context.

The sooner the relevant psychological research is done, the better.  If people commonly misuse material that impeaches a man's credibility as a basis to argue ad hominem against a claim of the impeached man, this frequent illogic is very troubling, including if jurors commonly do that, as this can cause unjust trial verdicts.  

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                                                         Testing the new definition, and a disclaimer

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         Readers of The Solution to an Injustice in Trials can search for an argument that: 1) qualifies as an argument ad hominem under its full definition, and, 2) is logical.  I claim that no such logical argument exists.  Rather, the full definition of argument ad hominem (in the book) describes a fallacy, not a merely generally illogical form of argument, and the book includes a justification of this claim.

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       I disclaim any responsibility if I have not discovered the composition of the broadest ad hominem fallacy that exists.  But I do believe I have discovered that composition.  And if I am mistaken, the error/s can be corrected if spotted. 

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        The above two definitions of argument ad hominem can be put to practical use, in a proposed law, to counter effectively argument ad hominem in trials

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        In The Solution to an Injustice in Trials is the text of a proposed law that expressly bans argument ad hominem in trials.  The proposed law has criminal sanctions for criminal violators, as with perjury.  Both argument ad hominem and perjury can deceive jurors, and both can thereby cause unjust verdicts. 

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    The proposed law uses two definitions of argument ad hominem: the functionally equivalent definition (quoted above), and, the full definition (in the book). 

 

       The functionally equivalent definition is used to give the public fair notice of what is prohibited in trials by the proposed law.  The full definition is used in the proposed law for other purposes.  The full definition is of valuable use in the proposed law, for reasons explained in the book.    

 

        The proposed law provides examples of argument ad hominem, to give a concrete impression of each of the four sorts of argument ad hominem numbered in the functionally equivalent definition. 

 

         Unless a law is created that expressly prohibits argument ad hominem in trials, the injustice of argument ad hominem in trials will continue, and probably worsen, as shown in the book.

                               

                              The benefits of a law that expressly bans argument ad hominem in trials

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      If the government creates an Anti Argument Ad Hominem Law with various attributes,[1] and this law is enforced, this will counter the mega fallacy effectively and lawfully in trials, and no alternative will do so (as shown in The Solution to an Injustice in Trials). 

 

         Such enforcement will:

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1) serve Justice for the parties in trials,

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2) spare the trial and appellate bench, and the bar, much more work, in the long run, than if the required law is not enforced, by substantially preventing, with credible deterrence, argument ad hominem in trials,[2]

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3) by such prevention: i) save much money for both the parties in trials and taxpayers (who fund the court system), and, ii) spare many jurors from the mental work and emotional pressure that argument ad hominem causes, which protection is both fair to them and serves Justice for the parties, and,

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4) probably raise the public’s opinion of lawyers’ ethics[3] and of the judicial system as a whole, which is beneficial because public respect for the rule of law is important to its efficacy.

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      A good side-effect of the proposed Anti Argument Ad Hominem Law is that some trial lawyers will study some of their cases for trial more carefully than they currently do, given: their new duty under this law to provide notice before trial of an intent to use “risky material” (Section 2 of the proposed law), and, the option of trial counsel to seek “judicial permission” before trial to make an argument in the trial that might be misunderstood to be an argument ad hominem (Section 48 of the proposed law).  Improved trial preparation by lawyers serves the interests of Justice.

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     Also, if the government creates an effective Anti Argument Ad Hominem Law this will make the new definition very widely available, and that would probably benefit society in ways unrelated to trials,[4] and, benefit the government personnel who created the law.[5]

 

[1] These attributes are stated on page 48 of The Solution to an Injustice in Trials.

 

[2] This includes arguments ad hominem that use bigotry and prejudice about a person, such as based on any of the person’s: race, sex, religion, national origin, ethnicity, mental or physical disability, age, sexual orientation, or socioeconomic status.  An effective Anti Argument Ad Hominem Law would help to exclude from trials bigotry and prejudice about a person.

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[3] In November 2012 Gallup recorded that in the U.S. only 19% of the public rated the honesty/ethics of lawyers as high or very high, 42% rated lawyers’ honesty/ethics as average, 28% rated lawyers’ honesty/ethics as low, and 10% rated lawyers’ honesty/ethics as very low.    Nurses scored best, of whom 85% of the public rated the honesty/ethics as high or very high, and car salespeople scored worst, of whom 8% of the public rated the honesty/ethics as high or very high.  http://www.gallup.com/poll/1654/honesty-ethics-professions.aspx

 

[4]  When a politician or anyone else regularly in the public eye argued ad hominem, the media could - and probably sometimes would - rightly criticize that person’s argument and show how it commits the mega fallacy.  Such criticism would probably reduce the amount that some such people argue ad hominem, and might even help some politicians to focus on being constructive for society.  And enforcement of an effective Anti Argument Ad Hominem Law would result in the new definition being additionally publicized, that is, beyond the definition just being published in that law and inThe Solution to an Injustice in Trials.   

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[5] This personal and honorable benefit is described in The Solution to an Injustice in Trials in its Appendix Section 13, under: 1) the sub sub-heading Self-improvement, which is under the sub-heading “Rossian ethics”, and 2) in relation to attaining eudaimonia, under the sub sub-heading Aristotle’s ethics, which is under the sub-heading “Virtue ethics”.

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                               The overall significance of argument ad hominem / the mega fallacy

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      I label the broadest ad hominem fallacy that exists synonymously “argument ad hominem” and “the mega fallacy”.  The label “mega fallacy” is apt because this fallacy is very broadly applicable to human ideas.

 

       Arguing ad hominem and lying have something very important in common: both can deceive people.

 

       Deception can be highly destructive, be it in a trial or in a non-trial context.

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      In a trial deception can result in an unjust verdict, whether the deception is caused by lying or is caused by argument ad hominem.  There is already a law that prohibits lying in a trial about a material issue, the law of perjury.  But a law is needed that expressly prohibits arguing ad hominem in a trial, in order to counter this quite common injustice effectively.  This necessity is shown in the book.

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      Of course deception outside a courtroom context can also be highly destructive, such as in politics or in everyday life, whether the deception is caused by lying or is caused by argument ad hominem, or is caused otherwise.

 

       The composition of lying is simple and easily understood: an intentional misrepresentation made with an intent to deceive.  In contrast, the full composition of argument ad hominem is complex, and requires about 140 pages to describe, and so the full composition is not easily understood.  But what makes lying significant is not its simplicity but its destructive consequences, and similarly what makes argument ad hominem significant is not its complexity, but its destructive consequences.

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        Lying is more insidious than argument ad hominem in that even people thinking logically can be deceived by lying, whereas, people thinking logically cannot be deceived by argument ad hominem, because it is a fallacy, an invariably illogical form of argument. 

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       However, everybody thinks illogically part of the time, and some people think illogically much of the time.  What people think is often influenced by emotion, not logic.   If people only thought logically, argument ad hominem would deceive nobody, and so would have far less significance than it has.  Argument ad hominem contains an emotional aspect, and this aspect is what makes argument ad hominem sometimes deceive people.  This emotional aspect is described in the book, for the first time, in what I call “Commonality 4”: 

 

“COMMONALITY 4) The man indicated in Commonality 1, as portrayed in the argument (in Premisses 2 and 1), and, the worth of his alleged idea, as judged in the conclusion, both have the same emotional resonance, both negative or both positive, e.g. a bad man’s idea is false (both negative), or a good man’s idea is true (both positive).207

 

207 The psychology that underlies Commonality 4 is not part of Commonality 4, has not been researched by psychologists, but includes this: for most people, from childhood, to reject a man’s idea is easier if they dislike him, and to accept his idea is easier if they like him.  Argument ad hominem, when it persuades, at least sometimes exploits this emotional tendency.  The psychology that underlies argument ad hominem is discussed more in Part I, under the sub-heading The prejudicial potential of argument ad hominem.”

 

   Given the destructiveness of argument ad hominem, due to its power to deceive, psychologists should research its power to deceive, which they can now do, for the first time, because the full composition of argument ad hominem has only recently been discovered.  That full composition is stated, for the first time, in The Solution to an Injustice in Trials (in Part II).

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      Argument ad hominem is quite common in human disputes, be they in court, in politics or in everyday life. 

 

     Effective democracy depends partly on an electorate that is mostly able to reject argument ad hominem as illogical. Rationality is crucial for effective democracy.   Thus an electorate that is well-educated about argument ad hominem and its persuasiveness, despite it being illogical, is far preferable to a gullible electorate that is easily swayed by argument ad hominem, unless, one’s objective is to destroy or weaken a democracy.   The world has dictators and other people who have that objective.

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      A politician or other person who has been identified correctly as an intentional arguer ad hominem who aims to deceive by their argument ad hominem, is intellectually dishonest.  What such people say should be examined dispassionately for whether their words are argument ad hominem, or false, or both.

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      In the book I describe 48 basic species of argument ad hominem.  These species differ by: 1) which of four sub genera they belong to (critical, laudatory, circumstantial, or critical & circumstantial), and 2) by which of eleven criteria of the worth of an idea they use in judging the worth of a man’s idea.  The bad news is that only three of these 48 species were previously identified (one by Plato and two by Aristotle).  The good news is the remaining 45 species are now known, and are described in the book.  

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      To know the full breadth of applicability of the mega fallacy requires either reading the description in the book of the fallacy’s full composition, or, discovering its full composition for oneself.  Sufficient here, to give  some sense of the mega fallacy’s major significance, is that the vast majority of ideas that people have in life can be illogically rejected (or illogically upheld) in argument ad hominem, including: all assertions of fact, and the vast majority of assertions of probable fact (with the exceptional logical circumstances identified in the book, and specifically excluded from the described fallacy, so that it is a fallacy, not just a generally illogical form of argument).

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       Lying in a trial can be undetected by the court, and, argument ad hominem in jury deliberations can also be undetected by the court. 

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      Sec. 49 of the proposed new law (which law is stated in the book) concerns invalidation of jury verdicts tainted by argument ad hominem, and related measures.  These measures include permitting jurors to inform the trial court of argument ad hominem in jury deliberations, and, encouraging jurors “… to inform the trial court, at the earliest opportunity, of any prejudice-based statement concerning the case that was presented before or during jury deliberations to a juror or jurors by anyone, including by a juror, including any such statement based on prejudice regarding a person’s: race, sex, religion, national origin, ethnicity, mental or physical disability, age, sexual orientation, or socioeconomic status.”  Sec. 49 (e).  The mega fallacy can deploy every sort of bigotry and prejudice about a person.  Social media should take note: hate speech and argument ad hominem intersect.

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      So, whether one supports or opposes: justice in trials, rational democracy, or logical argument in everyday society, argument ad hominem is very important.

     If computers (including artificial intelligence) can identify argument ad hominem accurately, this would be highly significant, given the destructiveness of argument ad hominem.  Social media companies could use computers to flag suspected argument ad hominem for their users.  Judges and lawyers could use computers to flag suspected argument ad hominem in trials and in court-filed documents.  Journalists could use computers to flag suspected argument ad hominem in politics and in other public discourse.  And perhaps one day the public could regularly use its own computers to flag suspected argument ad hominem in text or audio, like some people regularly use their computers to check spelling in text.

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      Given the destructiveness of argument ad hominem, computer and language experts should determine if computers can be made to identify argument ad hominem accurately.  Computer and language experts can now make this determination, for the first time, because the full composition of argument ad hominem is stated, for the first time, in the book.

 

      Artificial intelligence is already known to be formidably accurate in its decisions within tightly defined topics, such as the potent accuracy (but not infallibility) of AlphaZero in chess.  Whether the book's approximately 140 page description of the composition of argument ad hominem is sufficiently tightly defined for artificial intelligence to identify argument ad hominem accurately, is a very important question.  We do not want computers categorically telling all of society what is illogical, but we surely should use computers to flag suspected argument ad hominem in some walks of life, if and when computers are usefully accurate in this regard.

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                                  When, if ever, will a law expressly ban argument ad hominem in trials ?

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      Christopher Columbus took about two months to sail across the Atlantic Ocean.  But he required about seven years to raise the funding for his journey of discovery.  The funding was finally provided by Spanish monarchs, Ferdinand II and Isabella I. Apparently, for Columbus, obtaining backing was more difficult than sailing across the Atlantic.  Other matters competed for the attention of Ferdinand and Isabella, such as expelling the Moors from Spain.  To obtain approval from the powers that be, regarding a new idea, is sometimes difficult.  Other matters than preventing argument ad hominem in jury trials compete for the attention of today's law-makers, such as the Covid-19 pandemic.  

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       Before the Covid-19 pandemic America's federal law-makers (Congress and the U.S. Supreme Court) and the United Nations were notified of the possibility of a law that expressly bans argument ad hominem in trials, and were mailed The Solution to an Injustice in Trials.  But whether anyone in any government has considered the text of the proposed law (which is stated in that book) is another matter.   The last sentence of the Epilogue in The Solution to an Injustice in Trials is: "Nations fortunate enough to have a present opportunity to create an effective Anti Argument Ad Hominem Law should seize the opportunity, because fortune is fickle."  This was written before the Covid-19 pandemic.  After the pandemic ends perhaps the above-quoted sentence will be heeded, given the considerable benefits of creating such a law. The sooner such a law is created the better, all other things being equal. 

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         The American government should create an effective Anti Argument Ad Hominem Law sooner or later

 

      Sooner or later the American government can fairly be said to have an ethical duty to create such a law.  This ethical duty arises under the principles of ethics of Bentham, Kant, W.D. Ross, Aristotle’s ethics and other virtue-based ethics, as shown in The Solution to an Injustice in Trials.  Precisely when that duty arises depends on the state of competing priorities for government.