INTELLIGIBILITY, PRINCIPLE OF

An immediate and necessary judgment or law, commonly enumerated among the first principles, asserting that everything that is, in so far as it is, is intelligible; or that every being is capable of justifying itself, of explaining itself to the intellect, of answering the question "Why?" The conviction that there is an answer to be known inspires the attempt to know. When, for example, one asks why stones sink while logs float, the asking implies that reality provides a knowable answer, even though this is not yet known. Such a conviction is an implicit acknowledgment of the principle of intelligibility.

Justification. Since the principle of intelligibility is a first principle, and hence cannot be deduced, it follows that it cannot be directly proved. Therefore the only justification this principle admits of is indirect, that is, by showing that the principle cannot be denied without contradiction.

If one could deny that being is intelligible, this negation would be a judgment, which one would intend to elicit as true. However, intending to elicit a judgment as true, one intends to exclude unconditionally its contradictory assertion. Hence one can intend to elicit a judgment as true only insofar as the act of judging affirms an objective norm, the norm of being, as justifying the unconditional exclusion of the contradictory judgment, that is, insofar as one affirms being itself as justifying the judgment one elicits.

One could, therefore, deny that being is intelligible only dependently on affirming being itself as justifying this judgment of the intellect. However, being as justifying the judgment is being as intelligible, since it is being as that to which the intellect is conformed. Hence one could deny that being is intelligible only dependently on affirming that being is intelligible. This means that the negation of the intelligibility of being contradicts and eliminates itself; or that the denial of the principle of intelligibility is impossible.

It is to be noted, however, that the contradiction does not appear by an inspection or analysis of the terms of the negation, as it does, for example, in the negation that a circle is round. Rather the contradiction is between the act itself of denying and the content denied. Hence, the necessity of the principle of intelligibility is not merely a necessity of idea, but is one of act, of being: the necessity is not merely logical, but it is primarily ontological.

Application. The principle of intelligibility implicitly affirms that every being, even before it is known, conforms to the exigencies or laws of the intellect. This principle, then, affirming that being is necessarily intelligible and cannot be absurd, affirms that the act of being is intelligibility, or affirmability, outside of which there is no intelligibility. Hence the act of being is the fullness of intelligibility (see being; existence). Everything, therefore, is intelligible insofar as it is or verifies the act of being (St. thomas aquinas, Summa theologiae 1a, 16.3). Its act of being is its own light (In lib. de caus. 6), and by its act of being, it is synthesized with the totality of intelligibility. Hence, everything that is must be fully intelligible by reason of the act of being. It follows, therefore, that only that being that is fully identified with the act of being and hence is unlimited act of being, namely, god, is of Himself fully intelligible or is pure affirmability.

Every other being is of itself intelligible only in the measure in which it has the act of being, in the measure of its inadequate identity with the act of being. The measure in which it has the act of being is its essence. The properties of that being are intelligible by its essence. However, its essence itself is not intelligible by itself, but by the act of being. Since it is inadequately identified with the act of being, it has the act of being limitedly. The mind is therefore referred beyond this being itself for the complement of its intelligibility. Of itself alone such a being is not fully intelligible or affirmable, yet the conditions of full intelligibility by which it is affirmable must be given in being. This is to say that its intelligibility is completed by its relation to the cause of its being, God. It is not fully intelligible by the act of being precisely as found in this being, but rather as dependent upon the subsisting act of being. In this way the principle of intelligibility, when applied to finite being, evolves into another principle, namely, the principle of causality.

Although God, the finally implied justification of the principle of intelligibility, is of Himself the most intelligible, He is not so for man, who first finds intelligibility in material reality. Hence the fullness of intelligibility affirmed in the principle of intelligibility remains beyond the grasp of the human intellect. However, the principle of intelligibility affirms a coherent totality of intelligibility, and urges man on in his quest for an ordered, unified explanation of the endless multiplicity and facets of the universe. It guides and governs his search for truth and his rejection of error, since it enables him to know that whatever is opposed to the intelligible is impossible and absurd.

See Also: knowledge; falsity; absurdity

Bibliography: r. garrigou-lagrange, God: His Existence and His Nature, tr. b. rose, 2 v. (5th ed. St. Louis 1934–36) 1:15–25. j. maritain, A Preface to Metaphysics: Seven Lectures on Being (New York 1939). j. owens, "The Intelligibility of Being," Gregorianum 36 (1955) 169–193.

[f. p. o'farrell]