Truthfulness is the moral fundamental attitude of the value-responding relation to truth — the habitual disposition of the person to orient her speaking, promising, and self-presentation toward truth. It is a virtue, not a maxim: not a rule one applies, but a constitution of character.
Hildebrand: Value-Response
Dietrich von Hildebrand determines truthfulness in his Ethics (1953, ch. 18, 22) as one of the fundamental virtues of the value-responding constitution of the person. The liar does not primarily injure the hearer (though he does that too); above all he sets himself against truth as a value. Truthfulness is the person’s positive response to the value of truth; the lie is the value-contradicting response.
The ethical point: truthfulness is not a prudence-based compromise (“honesty is the best policy”), but a response grounded in the value of the matter itself. Whoever is truthful is so for the sake of truth.
Spaemann: Truthfulness and Personhood
Robert Spaemann (Persons, transl. Oliver O’Donovan, Oxford University Press 2006, ch. 6) shows the ontological depth: being-able-to-lie presupposes the obligation to be truthful. Only a being that must be truthful can lie. Animals dissemble, but they do not lie — because they lack the relation to truth as a personal obligation. An AI system produces what is false, but it does not lie — because it lacks the possibility of being truthful (cf. truth-indifferent AI utterance).
Thus truthfulness is an essential characteristic of personhood: only persons can be truthful and only persons can lie.
Augustine and the Tradition on Lying
Augustine (De mendacio and Contra mendacium) determines the lie as a statement against the speaker’s inner conviction with the intention to deceive. This determination requires three things: a speaker, an inner conviction, a deceptive intention. All three require a personal subject with original intentionality and free will.
The later tradition (Aquinas, Kant) discussed Augustine’s rigorous position — may one lie in dire straits? — without touching the basic concept: truthfulness is the norm, the lie its violation.
Searle’s Formal Reflection
In speech-act theory, truthfulness is mirrored in the sincerity condition of the speech act (Searle, Speech Acts, 1969): whoever asserts that p expresses the belief that p. Whoever asserts without the belief lies — and the concept of the lie functions only because the sincerity condition can be formulated. Without a formal-pragmatic relation to truth there is no speech act in the full sense (cf. speech act).
Pieper: Language and Power
Josef Pieper (Abuse of Language, Abuse of Power, 1970) shows the social dimension: where the relation of language to truth is renounced — in sophistry, propaganda, advertising as a form of language — the word turns into manipulation. Truthfulness is not only an individual virtue but a condition of the personal shared world. A society that abandons truthfulness loses its language as a medium of encounter.
Truthfulness Toward Oneself
Truthfulness is not only speaking-to-others, but also self-knowledge: the readiness not to deceive oneself, not to gloss over what is one’s own, to resist self-deception. Kierkegaard formulated this as a central existential task; Spaemann calls it “sincerity toward oneself.”
Truthfulness and AI
The truthfulness of an LLM is ontologically excluded — not from a defect, but from a structural lack. There is in the LLM no speaker who could have a belief; there is no person who could set herself against or for truth as a value. What appears there as an “assertion” is a truth-indifferent AI utterance — structurally outside the truthfulness–lie polarity.
Ontological Classification
- is a virtue of the person
- is the condition of the truthful statement and thereby of the speech act in the full sense
- constitutive for: dialogue, discursive capacity
- essential characteristic of personhood: only persons can be truthful and only persons can lie
- mirrored formally in: the sincerity condition of the speech act (Searle)
Sources: Generated by querying the Personhood ontology.
Further sources:
- Hildebrand, Dietrich von: Christian Ethics. New York: David McKay, 1953.
- Spaemann, Robert: Persons. The Difference between “Someone” and “Something”. Transl. Oliver O’Donovan. Oxford: Oxford University Press, 2006.
- Augustine: De mendacio (CSEL 41); Contra mendacium (CSEL 41).
- Aquinas, Thomas: Summa Theologiae II-II, qq. 109–113.
- Kant, Immanuel: On a Supposed Right to Lie from Philanthropy (1797). Academy Edition, vol. 8.
- Pieper, Josef: Abuse of Language, Abuse of Power (1970). (German: Mißbrauch der Sprache, Mißbrauch der Macht.)
- Searle, John R.: Speech Acts. Cambridge: Cambridge University Press, 1969.
- Habermas, Jürgen: The Theory of Communicative Action, vol. 1 (1981).
- Frankfurt, Harry G.: On Bullshit. Princeton: Princeton University Press, 2005.