Then, what is truth?

All sources are equal,...

Are all of these sources relevant? In polite company, people ignore at least Fundamentalism, Subjectivism and Coincidentialism. But are they are justified in doing so?

Is there a true source of truth? We have already discussed that we can not decide on the truthfulness of our source, other than by referring to that same source. The question for the "true source of truth" sends us into an infinite regress.

This defeats the goal that Fundamentalism, Subjectivism or any other source may be proved to be 'false'. In this sense, we are committed to pluralism.

There are other problems. Even if we accept Empiricism, it is not clear how we could prove by sensory perception that Empiricism is the right doctrine. Or if we accept Rationalism: is it intuitively clear that intuition is the source of truth? Not to me...

but some are more equal than others

Even if no source can be singled out as the true one, there are still reasons why one source might be preferred over another.

necessity

Necessary sources are pre-supposed by the notion of truth itself.

The truth of a statement presupposes that one understands the statement; which in turn requires human reason. So, Rationalism is presupposed in any true statement. It is a necessary source; we can not switch off our rationality.

usefulness

Utilitarian arguments for a source hinge on its usefulness. A source may be useful to mere survival, or to human motivators such as wealth, power and attention.

consistency

When we use the word 'true', we intend to discriminate between truthful and false statements. A source which would deem any statement true, conflicts with that intention.

The necessary source of rationality appears to entail the law of non-contradiction, which states that from a single inconsistency, any arbitrary statement can be proved. This is clearly an undesirable result, as it defeats the discriminatory quality of truth.

Thus, consistency may be demanded from a source.

objectivity

When one claims that a statement is true, one intends that this statement is true for everyone else as well. Truth is intended to be an objective quality.

univocation

When one claims that a statement is true, one intends that this statement has a non-equivocal, non-ambiguous meaning. 1

An example of an equivocal statement is: "In prison one is free from rain, sleet or snow. Therefore, freedom can be found in prison." Another, beautiful example is provided by Thomas Kuhn: "In the Ptolemaic system planets revolve around the earth; in the Copernican they revolve around the Sun." The equivocation is revealed when one considers that in the Ptolemaic system the moon is a planet and the earth is not, while in the Copernican system the opposite is true. "For no univocal reading of the term 'planet' is the compound sentence true." ¹

nominality

When one claims that a statement is true, one intends that this statement has an actual meaning. There is a category of words (nomen) that has no definition and thus lacks a meaning. Let us call these words "nominal". The 'primitive terms' or the 'undefinables' that we encounter in mathematics might be considered nominal. In most religions, the term 'God' is nominal.

A statement about a nominal term can itself also be called 'nominal'. For nominal statements, no truth-value can be derived. However, truth can be posited for them, in which case we call them axioms.

One may also take a different point of view: that the axioms serve as definitions of our nominal terms. A striking example of this is encountered when one asks for a definition of God. The common answer is a list of axioms describing everything all there is to know about God; God is love; God is the beginning and the end; God is the Creator; et cetera.

One also encounters terms with previously valid definitions which are being used in a nominal way. Political discourse is rife with examples of this abuse of nominality..

Equivocation, subjectivity and nominality are closely related. Arguably, they are instances of one meta-principle: the absence of an isomorphic relation between truth-bearer and meaning.

truth-bearers

What have we achieved so far? As a first step we have summed up the sources of truth that people have used historically. Our second step was an analysis of the implicit intensions of a truth-claim. We have taken the human actuality as a point-of-departure for our analysis of the notion of truth. Alternatively, we could have departed from an idealized theory or a formalized language, but only at the risk of restricting ourselves, and being left with a maimed notion of truth.

Generally, truth is supposed to be a predicate of truth-bearers. And these truth-bearers are supposed to be statements or sentences. But this contradicts human actuality. We frequently hear talk of “a true story”, “a false account of affairs” or “a perjurious testimony”. Only in philosophy do I encounter false or true sentences.

Let us, for argument’s sake, accept an account (of affairs) as our truth bearer. Certainly, some accounts can be summed up in a single sentence. Other accounts encompass a multitude of sentences.

Since (in)consistency is a quality of a multitude of (atomic) sentences, but not of a single sentence, we can apply our demand for consistency to accounts. Also, our demand for objectivity and univocation now apply to the entire account.

As an example, consider a quote which is attributed to Kofi Annan, the present chairman of the United Nations,

Intelligence is one commodity equally distributed among the world's people.

Here, intelligence can not be something that is measured in IQ-tests, since people have different IQ-scores. But neither does Annan provide an alternative definition.