There’s been much discussion about ‘fake news’ recently, leading to renewed arguments on the nature of truth. In fact, most people are totally disinterested in understanding the nature of truth, but instead only wish to prove their own view irrefutable, which is actually impossible. This topic explains why, via examination of the formal definition of the meaningfulness of 'post truth,' within the context of the truth theories of modern philosophy.

Was this Tweet true because Trump was certain evidence would be found later?
Was this Tweet true because Trump was certain evidence would be found later?

The Postulation of 'Post Truth' as Truth

Rhetorical assertions have arisen whereby people state what they wish to be true as being true, without having any evidence at the time. Then they strive to find facts to prove that truth afterwards, giving rise to a dual meaning of ‘post-truth’ in the post-truth era. One famous example, illustrated above, is President Trump’s recent assertion that President Obama was ‘wiretapping’ his phone. President Trump held that he was telling the truth because he believed it certain that evidence will be found, regardless that he had no evidence at the time, and he had heard an assertion to this end. When the claim he had heard was proven false, he continued to hold that he knew Obama had wiretapped him, because he was certain other evidence would be found.

While people might well be inclined to ridicule such a belief out of hand, one can actually find a basis for its meaningfulness in formal logic--a fact that has made post-truth conceptions more successful than many expected. This is because one advanced thinker on the semantics of truth is Donald Davidson, who is an absolute anomalous monist (which holds there are only ideas, or mind, or matter, or phenomenological experience, or language, but it cannot be known which; notwithstanding, Davidson has his own twist on that, but it is beyond the scope this topic can cover). Davidson deduces that truth is ultimately undefinable, yet through our ability to reason meaningfully, truth can be known. However, people do not know that they know the truth until after they have stated it. This is a deduction from the observation that such truth can only be determined empirically after the statement is made. For example, Davidson states, people can know that the sun will rise tomorrow; however, people do not know that they knew that until after the sun has risen.

Of course, not everyone agrees with Davidson, but it is nonetheless a formal explanation of how ‘post truth’ has become meaningful. However much one might attempt to dismiss the new post-truth doctrines as obviously absurd, it is not so easy, because of the complexities of formal definitions of what truth actually is.

The Formal Definition of Truth

In the school of formal logic, truth is found by evaluating propositions (the formal representation of equivalent statements) according to a "theory of meaning" (here referred to as semantics). Before considering semantics in more detail, a descriptive framework follows that is commensurate with the thinking of Russell, Whitehead, Moore, Wittgenstein, Ramsay, Tarski, Carnap, Ayer, Strawson, Quine, Putnam, Searle, Sartre, Mendelson, Austin, Kripke, Popper, Kuhn, and Davidson. All of these thinkers advance rational doctrines based on various premises, with differing degrees of roots in prior writing by Plato, Aristotle, Locke, Hume, Kant, Frege, Leibniz, Boole, and Husserl. Here is Aristotle's ‘Square of Opposition’ which has remained the basis of almost all formal logic for ~2,400 years.

Aristotle's ‘Square of Opposition’ is the Foundation of Formal Truth
Aristotle's ‘Square of Opposition’ is the Foundation of Formal Truth

While these thinkers discuss the relative merits of each doctrine, they do not hold their own premises to be dogmas (principles that are incontrovertibly true). Instead, they work communally to define how much truth can be understood via reason. As such their doctrines are together considered a school.Across the school overall, the following kinds of truth exist, depending on the proposition's type. Note that this summary cannot capture the details of each thinker's views, rather instead referring to them in general; and that not all doctrines include all types.

  1. Propositional truths

    Via formal definitions of logical systems, these truths are established by syntactic consistency with core axioms. The core axioms themselves describe the formal systems, and so truths of this kind are necessarily true, in accordance with syntactic rules which are themselves formally defined as logical propositions. The most frequent example is mathematical equations. These propositional systems can also define rules of deduction and inference without introducing meaningfulness and causality. If the doctrine admits the existence of truth, then the truth evaluation itself requires some semantic definition of ‘truth,’ in order for the proposition to be assessed. In all such cases, the process of evaluating the proposition’s truth value only requires syntactic analysis.
  2. Empirical truths

    These must be determined via ratification, by observation of material objects, states and events, as long as the propositions describing material objects, states, and events are logically coherent. If the observation verifies the proposition, then the result of the observation is the proposition's truth value. The specific and exact nature of truth itself depends not only on facts or data, but also on the epistemological factors relating the proposition to the material world in different metaphysical systems, most predominantly in the theories that define the relation of subject and predicate to objects, states, and events in the physical world. These theories always add semantics to the syntactic relationships. 'Internal' states, resulting from consciousness, are also evaluated empirically. The nature of consciousness itself is part of the epistemology.
  3. Causal truths

    These again first must be generally consistent within the rules of propositional calculus, so they must not contain any syntactic fallacies of deduction or inference. These are the most complicated forms of truth to evaluate, in particular because causal relationships cannot ever be proven necessarily true. They can only be proven not to be false. That is because, in propositional logic, Aristotle’s law of excluded middle holds that any proposition is either true or false; but in the statements of causality in real-world language, there need be no excluded middle. Hence, proving that a statement of cause is not false does not imply that it is necessarily true. Metaphysical factors also influence the relation of the subject and predicates in the cause, to the subject and predicate of the result.
  4. Compound truths

    While those are the basic forms of truth, the truth of many statements relies on combining two or more these forms together. For example, the statement "there are three trees" relies on syntax from the first system to determine the nature of the number, and combines it with empirical evaluation from the second system to count the number of objects.
  5. Scientific truths

    Most commonly believe they know that the sun will rise tomorrow, usually because of many empirical observations of prior days where the sun did rise, leading to the logical deduction that it will rise again tomorrow in the same manner. Logically, one cannot know whether the belief is true that the sun will rise tomorrow until after the event has occurred. But in most cases, when sufficient empirical validation of many prior similar events has occurred, it is loosely assumed true that the same future event will occur again in the same circumstance. This axiom of probabilistic certainty is the foundation of prediction in much scientific theory. The extrapolation of this axiom is the creation of the scientific method, which is designed to define the minimum number of observations necessary to corroborate a theory. As per the rules for causal truth, theories can only be corroborated and not be proven true; but modern science theory might still call a theory true based on the axiom of probabilistic certainty.
  6. Contractual truths

    Beyond that basis, there are some other very specific forms of truth in philosophy. For example, there are self-generating truths in linguistics, such as promises, statements of intent, contracts, and some statements of belief, which all become existent by their own statement. One should be aware these kinds of truth have limitations. For example, after making promises, it becomes true that promises were made, but the truth of the promise itself remains an indirect proposition, and still must be determined within the rules for the three basic forms of truth described above.
  7. Truth in theology, morality, ethics, law, and metaphysics

    Much confusion about truth has arisen in these fields, but by the above schema, the nature of truth itself is relatively simple. Briefly:
    • Theology strives to define that which cannot ultimately be proven.
    • Morality strives to define that which is good or bad for an individual.
    • Ethics strives to define that which is good or bad for a society.
    • Law strives to define that which is right or wrong.
    • Metaphysics strives to define what is real.
    In all these fields, the absolute truth of the assertions they make is undefinable. However within each of these fields, it is possible to evaluate the propositional consistency of statements within the formal systems on which they are based; and from that, to evaluate the truth of their propositions empirically, within different doctrines of the field. But when propositions across different doctrines contradict each other, it is not possible to evaluate which are true or false in absolute terms. It is only possible to demonstrate when the claims by each doctrine are coherent within the same doctrine, and therefore can only be evaluated as truthful within context. Note that this applies to metaphysics itself, and there are different metaphysical premises in different doctrines of truth.

The Semantics of Truth

According to all modern logicians, truth is the result of evaluating a proposition, but the relation between truth and the proposition itself can be different depending on epistemological considerations. While one might initially believe the nature of truth to be intuitively obvious, the semantics of truth are complex. This starts with the issue as to whether one believes that tautological propositions are true before any person evaluates them; in which case, the truths must exist independently in some abstract space independent of material reality. That introduces the metaphysical considerations.

  1. Classical realists hold that Platonic ‘ideas’ do exist independent of perception, and truth is discovered by cognitive correlation. Modern realists state only external material reality exists, and abstractions are simply known by common sense (as a result, many modern philosophers refer to classical realism as idealism). Dualists hold that there separate domains of physical materiality and conceptual ideas, both of which exist, and some hold tautologies are a priori true (are still truth regardless whether they are considered). Monists hold the known reality is only physical, or only exists in the mind, or something else. Some monists hold that truth can only be known phenomenologically (for experience). Other monists follow Wittgenstein's idea of logical positivism, which holds that language is the only thing which can be absolutely known. Such different perspectives change what is actually known when a truth is ‘discovered.’ For example, deflationary theorists extrapolate from logical positivism to hold that truth by correlation is all that exists, leading many skeptics to the popular post-modern idea of truth nihilism, although they are often unaware that such ideas rationally derive from logical positivism and instead believe themselves realists.
  2. Regardless how and whether propositional truth does exist independently of physical reality, a priori or not, empirical and causal truths may be properties attached to the proposition which are not ‘discovered,’ but rather ‘assessed.’ These latter cases introduce the meaningfulness of incorrect assessments, and how exactly something can be meaningful if its truth is beyond simple binary evaluation, such as for example, propositions which refer to non-existent objects or which contain metaphors. Thus the semantics of truth are not so simple, and become involved with metaphysical decisions defining the nature of reality, meaningfulness, and the definition of knowledge itself.
  3. There are also three separate positions on causality. Some hold that there is no causality without intent, and that it is otherwise simply a logical inference or deduction. The second main position is that intent does not really exist either, but is only an apparent phenomena created by the physical workings of the world. The third main group say one or both of those ideas are reductionist, and so do not give any meaning to the word 'because.' The different positions on intent may also influence truth evaluation of empirical observations on internal states, such as feelings.

Merit, rather than Truth

From the above summary, it is clear that a great deal of dispute exists on the nature of truth, which is greatly to the advantage of rhetoricians wishing to persuade others that their opinions are "the truth." In reality, most of those asserting that they know 'the truth' are not attempting to state the truth at all. Instead, they are making assertions about truth to persuade others to their point of view. If pressed, they justify this simply by claiming their belief is true in a circular manner, so this does not define any knowledge of truth at all, but rather is a religious belief (whether they themselves acknowledge the existence of religion or not).

With sufficient qualification as to one's preferred metaphysical and semantic foundation, it is possible to make statements that are true within context of that metaphysical belief. There always exist alternate possibilities. Indeed, according to truth nihilism, there is actually no such thing as 'truth' at all. So according to the school of formal logic, assertions of a person that some fact is undeniable truth remain an opinion, in all cases without exception.

When a statement can be found true in more than one metaphysics, and whose interpretation is more unambiguously framed within the presumed premises and resulting rules, then it may be considered to possess greater merit.
Hence, in modern metaphysics,
the merit of a statement
is considered more fruitful to consider
than the truth of a proposition

The Merit of Post-Truth Doctrine

Let us consider again the post-truth assertion that something is true when a person has no evidence, but is certain evidence will be found later, According the anomalous monist theories of Davidson, that statement might be proven true, with two caveats, here described with reference to Trump:

  1. The empirical evidence is extremely weak, compared to cases where people are making assumptions of knowledge based on far more extensive theory (such as, in the case of believing the sun will rise tomorrow, the predictive theories of physics, which are very well qualified in terms of the axiom of probabilistic certainty).
    1. Separate Senate, Congress, and FBI investigations have all reported that they can find no evidence at all that Obama 'wiretapped' Trump's phone.
  2. The administration has since attempted to make nonsensical allegations as to the existence of evidence at least three times, increasingly diluting any claim that Trump knew the truth, via some inference based on his claimed superior intuition, when he stated Obama was wiretapping him:
    1. First, Trump himself stated he heard the evidence on Fox News. Fox News issued a formal statement disowning the claim as 'fake news' the following day.
    2. The White House then claimed the British wiretapped Trump for Obama, which is not only against international law, but also was called "utterly ridiculous and should be ignored" by the British intelligence service, GCHQ.
    3. Some incidental collection on others in Trump's Presidential campaign was then found, which Trump himself then claimed as proof he was right. But the incidental collection was not on him, and was certainly not caused by Obama.
  3. Epistemologically, the assertion only becomes a meaningful proposition in Davidson's doctrine of anomalous monism.
    1. According to this doctrine, Trump may know the truth, but he still cannot claim he knows that he knows it, despite two months of intense effort to find evidence for his claim.

The same general response, in abstract, can be made on Trump's assertions that Clinton is a criminal, on which weight he is generally considered to have won the election. Note also that national surveys still show that 30% of all voters believe Trump about both Obama and Clinton on these issues.

It is therefore fair to conclude that Trump's claims to knowledge of truth can be construed as meaningful, but are of decreasingly little merit, even to the extent that the unlikely future appearance of evidence proving his original statements true could justifiably considered accidental.

However, that is far beyond that which most people who ‘just want to know the truth’ are ready to learn. So as things are, we are likely to be stuck in the post-truth era, wherein many similar truths are claimed with equally little merit, for a very long time.


Ernest Meyer