Trump, Truth, and Logic
Robert Hanna
Figure 1: Logical Trumpism in action (NYT, 2024)
The fundamental flaw in democracy and democratic politics is the malign manipulability
of people’s beliefs by means of intentional illogic, misinformation, and sophistry. In view
of Donald Trump’s resounding victory in the 2024 US Presidential elections, this is selfevident, even fully allowing for other substantive reasons explaining Trump’s election
win (Karp, 2024).
A.J. Ayer wrote Language, Truth, and Logic in order to tell the world about Logical
Empiricism (Ayer, 1935/1952). The purpose of this essay is to tell the world about what I
call Logical Trumpism. To the extent that the Logical Empiricists held that the choice of a
logic is non-cognitive because it’s strictly determined by human self-interest, and that, as
Rudolf Carnap famously put it, “in logic there are no morals” (Carnap, 1937: p. 52), then
Logical Trumpism can be regarded as a reduction-to-absurdity of Logical Empiricism.
But before we get to Logical Trumpism, I’ll provide a brief tutorial about truth and logic.
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Pontius Pilate mockingly asked “what is truth?,” and as J.L. Austin archly,
deflatingly, and wittily observed,
would not stay for an answer. Pilate was in advance of his time. For “truth” is an abstract
noun, a camel, that is, of a logical construction, which cannot past the eye even of a
grammarian. We approach it cap and categories in hand: we ask ourselves whether Truth
is a substance (the Truth, the Body of Knowledge), or a quality (something like the color
red, inhering in truths), or a relation (“correspondence”). But philosophers should take
something more nearly their own size to strain at. What needs discussing rather is the use,
or certain uses, of the word “true.” (Austin, 1964: p. 18).
So, Austin proposes to characterize the nature of truth via ordinary language analysis.
Now, here’s a different way that philosophers could “take something more nearly their
own size to strain at” when characterizing the nature of truth.
First, by a veridical appearance I mean anything X that appears as F, or appears Fly, or appears to be F, to any or all actual or possible rational human cognizers, just insofar
as, and precisely because, X is F. For example, if I say “It appears that Sweetpea the cat is
looking at me from the door of her cat-cave in my daughter’s apartment in Los Angeles,”
and what I say is indeed the case, as per the picture directly below–
Figure 2: Sweetpea the cat is looking at me from the door of her cat-cave in my daughter’s
apartment in Los Angeles.
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or “It appears that 2 + 2 = 4,” and again what I say is indeed the case, as per basic
arithmetic, then all the things I’m talking about are veridical appearances.
Second, by the manifestly real world, I mean the world as it can veridically appear,
or does veridically appear, to any or all actual or possible rational human cognizers or
agents.
Then, third,
a statement (judgment, assertoric belief, proposition, meaningful sentence, theory,
etc.) is true if and only if what it states (means, says, etc.) is manifestly real.
This characterization of the nature of truth (i) meets Austin’s anthropocentric
requirement on a philosophically adequate theory of truth, (ii) captures the pith-&marrow of Alfred Tarski’s intuitive linguistic characterization of truth (Tarski, 1943,
1956), and also (iii) specifically rules out any metaphysics of truth that requires the
existence of non-manifest or “noumenal” Really Real objects.
What is logic? Once upon a time, in a faraway land, I published a book on the
philosophy of logic, Rationality and Logic (Hanna, 2006a). In that book, I asserted that logic
is the a priori formal science of the universal principles or laws of truth-preservation via
the relation of logical consequence (aka logical entailment) between the premises and
conclusion of any argument, a relation according to which there’s no possible set of
circumstances (or: no possible world) in which all the premises are true and the
conclusion false. Now, every such argument is a valid argument; and necessarily, if all the
premises of a valid argument are true, then the conclusion must also be true, which is a
sound argument. Moreover, logical consistency is when one or more propositions that can
be jointly true, relative to an “interpretation” whereby meaning and truth are assigned to
every member of a set of statements, hence when no statements in that set are inconsistent
with themselves or with one another. By contrast, logical contradiction is either when a
proposition violates a logical law and is necessarily false, or when two or more
propositions cannot be either jointly true or jointly false. Finally, logical deduction is any
argument that unfolds strictly according to the relation of logical consequence.
Any formal science that generally models itself on logic as defined under that
definition can be called a “logic,” even if this formal science is either not strictly a priori,
or does not generate strictly universal principles or laws, or does not operate strictly
according to the relation of logical consequence. By classical logical systems I mean formal
systems representing logical consequence and valid inference that are (i) bivalent, by
which I meant that (ia) there are two and only two truth values, true and false, (ib) every
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sentence has a truth-value (i.e., there are no truth-value gaps), (ic) no sentence has more
than one truth-value (i.e., there no truth-value gluts, and (id) if a sentence isn’t true then
it’s false, and conversely (i.e., there are no extra truth-values) (ii) contain the sentential
logic of simple truth-functions (“not,” “or,” “and,” “if… then,” and “if and only if”), (iii)
contain names of individuals and monadic (one-place) and polyadic (many-place)
predicates, including identity, (iv) contain first-order quantification (“all” and “some”)
over individuals and/or second-order quantification over relations, including identity,
and (v) contain universal principles of non-contradiction (no sentences are both true and
false) and excluded middle (every sentence is either true or false, and there are no extra
truth-values). Such systems are consistent (no contradictions, and there’s at least one
interpretation in which all statements are true), sound (all the provable statements are
true), and complete (all the true statements are provable).
Kurt Gödel famously or notoriously showed that every classical logical system,
plus the Peano axioms for arithmetic, contains undecidable, unprovable statements and
is consistent if and only if it’s incomplete (the first incompleteness theorem), and also that
no such system can demonstrate its own consistency or contain its own truth-definition
(the second incompleteness theorem) (Gödel, 1931/1967). Therefore, mathematical logic
is inherently incomplete, and mathematics cannot be explanatorily reduced to logic.
Moreover, whereas, after A.N. Whitehead’s and Bertrand Russell’s Principia Mathematica
(Whitehead and Russell, 1910/1962), it was generally assumed by philosophers and
mathematical logicians that there must be One True Logic, it actually turned out that there
are not only conservative extensions of classical logical systems, that add one or more new
principles or laws to classical logic, for example, classical modal logic, while remaining
consistent, sound, and complete, but also deviants of classical logical systems, that reject
one or more of the principles or laws of classical logic, for example, (i) intuitionist logic,
which rejects the universal law of excluded middle and contains some sentences that are
neither true nor false, either because they have some other value, or have a range of such
values, aka three-valued logic, or many-valued logic, or because they have no truth-value,
aka truth-value gaps, and (ii) dialetheic logic, which rejects the universal law of noncontradiction and contains some provable sentences, aka theorems, that are both true and
also false, aka truth-value gluts.
So, it seems, not only isn’t there One True Logic, there’s also an unrestricted
multiplicity of logics, and that anything goes: this is known as the pluralism problem (see,
e.g., Hanna, 2006a: ch. 2). Nevertheless, whether complete or incomplete, and no matter
how deviant, necessarily, all of these logical systems preserve at least a minimal version
of the principle of non-contradiction: not every statement is both true and false (Hanna,
2006a; see also Putnam, 1983). Therefore, in my opinion, there must be a universal protologic, containing the minimal principle of non-contradiction and all the other logical
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notions presupposed and implied by this principle, which isn’t The One True logic, but
that’s also used procedurally in order to construct every other logic, and furthermore it’s
(i) a priori by virtue of being innately specified in the cognitive and practical capacities
of all actual and possible rational human animals (i.e., it’s transcendental) and (ii) noninstrumentally and unconditionally normatively grounded in human dignity (i.e., it’s
categorically normative) (Hanna, 2006a: chs. 4-7).
Leaving aside the problems of incompleteness and pluralism, however, the
deepest and hardest philosophical problem about logic is what’s called The Logocentric
Predicament: in order to explain or justify logic, logic must be presupposed and used,
hence any explanation or justification of logic is circular, and therefore logic is rationally
inexplicable and unjustified (Hanna, 2006a: ch. 3; Hanna, 2024: section 16.2.2). The
Logocentric Predicament is closely related to what’s called the problem of justifying
deduction (see, e.g., Dummett, 1973/1978; and Haack, 1976), which unfolds as follows. It
seems that there are only two relevant options for rationally justifying logical deduction:
either (i) a deductive justification, or (ii) a non-deductive justification, for example, an
inductive justification. But an inductive justification is too weak, and a deductive
justification is circular and more generally falls into The Logocentric Predicament. This
isn’t the place to argue for an adequate, definitive solution to The Logocentric
Predicament; but one promising possibility is that although the universal proto-logic is
indeed presupposed and used in the justification and explanation of every other logic,
whether classical or deviant, it’s neither circular in any vicious way, nor unjustified, nor
inexplicable, precisely because it’s (i) transcendental and (ii) categorically normative
(Hanna, 2006a: ch. 3).
Correspondingly, one of the core theses of Rationality and Logic is that rational
human thinkers are rationally capable of constructing any “alternative” or “deviant”
logic whatsoever, provided that the constructed logic obeys one simple principle, the
minimal law of non-contradiction, which, as we saw above, says that not every statement
is both true and false. Violations of the minimal law of non-contradiction yield a logical
phenomenon called explosion, which is universal inconsistency, or logical nihilism.
Now, ever since his election as US President in 2016, and especially in view of
Trump’s decisive popular-vote and Electoral College victory in the 2024 US Presidential
election campaign, it has become self-evident that he is self-consciously operating with a
highly deviant, highly devious, sophistical logic that is in fact in violation of the minimal
law of non-contradiction. This logic was fully on display, for example, during the first
presidential candidates’ debate with Kamala Harris, as per the image at the top of this
essay, but also throughout the seemingly endless campaign.
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I call Trump’s logic, the logic of mindfuck. The logic of mindfuck has two basic
principles.
First, the principle of alt-facts: you can assert or deny (or assert and deny) any
statement whatsoever, in any context, as desired. These assertions or denials are called
“alternative facts” or “alt-facts” (CNN/Conway, 2017). According to Harry Frankfurt,
bullshit is speech that systematically manifests a blatant disregard for truth, alongside a
pretended concern for truth (Frankfurt, 1988). Therefore, by virtue of the principle of altfacts, basically everything Trump asserts is bullshit. More generally, the purpose of the
principle of alt-facts is to mess with the mind of anyone who cares about truth, and
therefore sharply disagrees with Trump — whom he then calls “creators of FAKE NEWS.”
Second, the principle of unrestricted entailment: you can infer any and every
statement from any and every other statement, as desired. So, by virtue of the principle
of unrestricted entailment, Trump is not merely a truth-hater but also a logical nihilist. The
purpose of the principle of unrestricted entailment is to mess with the mind of anyone
who cares about logic and (minimal) consistency, and therefore sharply disagrees with
Trump—whom he then calls “COMMUNISTS” or “LIARS.”
In my opinion, as rational human animals, we’re not only rationally obligated but
also morally obligated to care about truth and logic (Hanna, 2006b). Therefore, as rational
human animals, we’re not only rationally but also morally obligated to identify, criticize,
and reject Logical Trumpism and Trump’s logic of mindfuck; and this is particularly
important and indeed urgent now that Trump and his Republican myrmidons have been
enabled by a substantial democratic majority for another four years. 1
I’m grateful to Scott Heftler for drawing my attention to the so-called debate between Donald Trump and
Kamala Harris on 10 September 2024 (see NYT, 2024), which I’d been resolutely ignoring, but which, by
virtue of seeing Trump’s demagogic mastery of intentional illogic, misinformation, and sophistry in action,
strongly inclined me to fear a Trump victory in the November election.
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REFERENCES
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(Hanna, 2024). Hanna, R. Science for Humans: Mind, Life, The Formal-&-Natural Sciences,
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(NYT, 2024). Goldmacher, S. and Rogers, K. “Harris Dominates as Trump Gets
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