Adequation of truth
| Latin | adaequatio intellectus et rei |
|---|---|
| Locus in Aquinas | Summa theologiae I, q. 16, aa. 1–2; De veritate q. 1, a. 1 |
| Branch | Metaphysics |
| Controlling authority | Catechism 39–43; Dei Filius; John 14:6 as confessed of God; Thomistic synthesis |
| Doctrinal standing | God is Truth and created intellect can know true being; the technical adaequatio is scholastic theology |
| School | Thomism |
Adequation of truth is the Thomistic account of truth as the conformity of intellect and thing, completed first in the judgment that affirms what is and denies what is not.[1]
Conformity of intellect and thing
In the disputed questions De veritate, question 1, article 1, Aquinas locates the true among the modes that follow upon every being in relation to another. Being as such is the first conception. The true adds the agreement of being with intellect, which he names the adequation of thing and intellect. Knowledge is a consequence of that conformity, not its substitute. The 1913 Catholic Encyclopedia's article on truth repeats this scholastic correspondence for logical, ontological, and moral truth.[2][3]
Summa theologiae I, question 16, article 1, then distinguishes where truth resides. Truth is primarily in the intellect, because the known is in the knower. Things are called true secondarily, as related to an intellect: artifacts as they match the maker's idea, natural things as they match the divine intellect that measures them and as they can cause a true estimate in us. The definition that truth is the equation of thought and thing therefore covers both aspects without making stones true only when someone looks at them.[1]
Judgment, not mere apprehension of a quiddity
Article 2 of the same question holds that truth, properly speaking, is in the intellect composing and dividing. Sense and simple understanding of what a thing is can be true as a thing is true, because they have the likeness of the object. They do not yet know that likeness as conformity. Only when the intellect judges that the thing corresponds to the form it has apprehended does it know truth as known. That is why a definition is called true or false by reason of an implied composition, not by a second little picture inside the first.[1]
The negative judgment is not an exception. It does not deny the reality of every predicate named; it denies the conjunction asserted. Adequation is therefore not a crude copy theory in which every mental image must resemble a material surface. It is the measured agreement between what is affirmed and what is. Error is a failed adequation in composition, not a private color of consciousness.
God as first truth and analogical speech
Question 16, article 5, identifies God as the first and sovereign truth, because his being is his act of understanding and the measure of every other intellect and being. That identification serves the confession of John 14:6 without collapsing created truths into one numerical quality in creatures. Created intellects have many truths; things are true by assimilation to the one divine truth. Dei Filius teaches that God can be known with certainty from created things by the natural light of reason, and the Catechism, 39–43, teaches that our names for God attain him analogically while remaining surpassed by the divine essence.[4]
Adequation therefore does not make God a proposition. In God there is no composition of subject and predicate. His simple act of intelligence knows all complex truths. Our adequation is measured, received, and capable of growth. Fides et Ratio later commends this metaphysical realism: the mind is not closed in itself, and truth is not a mere consensus of speakers.[5]
School definition under Catholic confession
The Church binds Catholics to the knowability of truth, the distinction of true and false judgment, the prohibition of lying, and the confession that God is truth. She has not defined Isaac Israeli's formula as a conciliar canon. Other Catholic philosophers may refine correspondence, or speak of manifestation and evidence, provided they do not reduce truth to sincerity, usefulness, or the mere coherence of a closed system.[6]
Humani Generis defends the certitude of metaphysical principles against a despair of reason. Aeterni Patris commends the scholastic account because it lets theology say that dogma is true of God, not only edifying for us. Adequation is the school's servant of that confession. It is not a fourth gospel. Used well, it keeps preaching from two equal failures: treating doctrine as mood, and treating the mystery as a diagram that exhausts God.
References
- Back to citation occurrence 1.0 Back to citation occurrence 1.1 Back to citation occurrence 1.2 Thomas Aquinas, Summa theologiae I, question 16, articles 1–2 — Primary account of truth as conformity of intellect and thing, residing first in the intellect composing and dividing, and analogically in things as related to intellect.
- Back to citation Thomas Aquinas, Quaestiones disputatae de veritate, question 1, article 1 — Disputed-question definition of truth as the adequation of thing and intellect, and of the true as a mode of being relative to knowledge.
- Back to citation Catholic Encyclopedia (1913), Truth — Public-domain account of logical, ontological, and moral truth as correspondence, with the scholastic adaequatio of intellect and thing.
- Back to citation Catechism of the Catholic Church, 39–43 — Authoritative teaching that purified creaturely language truly attains to God while remaining analogical and forever surpassed by the divine essence.
- Back to citation John Paul II, Fides et Ratio — Encyclical on the harmony of faith and reason, the enduring value of Aquinas, metaphysical realism, and legitimate philosophical plurality within Catholic faith.
- Back to citation First Vatican Council, Dei Filius — Dogmatic constitution on God the Creator, the natural knowability of God, the distinction and harmony of natural and supernatural orders, and the gratuity of revelation.