Criterion

CRITERION. - From the Greek κριτήριον, it is generally a norm or rule for recognizing, discerning (κρίνω = "I judge, I discern") a thing, a fact, a judgment. In philosophy it is for the most part identified with the criterion of truth and designates, in this case, the norm by which to distinguish the true from the false. But in a broader and somewhat improper sense, every means and instrument that serves or leads to the knowledge of the true is called a criterion: it is in this sense that reason, intelligence, conscience, and also reasoning, syllogism, induction, etc., are sometimes called criteria. In the first meaning, which is the most proper, the criterion is often identified with the motive of certainty, inasmuch as what is the norm for discerning the truth is also the principle determining certainty; consequently the expressive value of the term broadens, since the motives of certainty can be many and of various kinds. One therefore speaks of intrinsic and extrinsic, objective and subjective criteria, according as the motive of certainty is or is made to consist in a property inherent in the object of the judgment (evidence); or instead in a norm exterior to it (divine authority, universal consent); or in a subjective modality of knowledge (the clarity of perception, taste, feeling).

The question of the criterion of truth was posed in the history of philosophy from the time when skepticism had denied the possibility of certainty, precisely because of the supposed lack of a sure and infallible norm by which to distinguish the true from the false (Sextus Empiricus, Adv. Math., VII, 195). Already Socrates, against the relativism of Protagoras, thought he could point to a universal criterion of certainty in natural and common thought. And similarly the Stoics sought a criterion of truth in those representations that are found alike in all men (κοιναὶ ἔννοιαι) and by their particular evidence force our assent (cf. N. Festa, I frammenti degli stoici, I, Bari 1932, pp. 33-36). But it is in modern philosophy, and even more after Kantian criticism, that the question has had ample development, with all possible solutions. R. Descartes placed the ultimate criterion of certainty in clear and distinct perception; H. Spencer in the inconceivability of the contradictory; T. Reid in the common sense that leads us almost by instinctive necessity to the affirmation of certain principles that cannot be eradicated from reason; F. E. Jacobi in a spiritual feeling that, prior to and beyond every intellectual perception, assures us of the true; pragmatism (W. James) in the function of utility or necessity that a proposition or a doctrine demonstrates for life; voluntarism (Ch. Renouvier) in the free affirmation of the will; immanentism and actionism (Laberthonnière, Blondel) in the demands of life and action. Meanwhile another current sought the criterion of certainty in an exterior norm: P. Huet in the authority of divine revelation; L. de Bonald in the tradition that preserves and transmits divine revelation; F. Lamennais in the universal consent of the human race.

Traditional gnoseology does not deny the positive value of these criteria: both authority and feeling, instinctive inclination, life, action, faith, practical utility have their part in facilitating and supporting, alongside the intelligence, the knowledge of the true, which is often a conquest in which man must engage all his forces. But, granted the primacy of the intelligence, none of the criteria indicated can count as the one or ultimate criterion to which truth and certainty must appeal. There are undoubtedly in man states of certainty that arise and are founded, at least in part, on feeling, such as, for example, aesthetic certainty; but if one remains in the field of intellectual knowledge, the supreme criterion, in the sense of a universal motive of certainty (for the search for a single criterion, understood as an infallible exterior norm that would allow us in every case to discern the true from the false, would be vain) is, as St. Thomas already affirmed (In III Sent., dist. 23, I, 2, sol. 3), evidence, understood as the objective necessity of being and therefore of the judgment. Certainly evidence, taken in a generic sense, and when its concept is not determined in function of the metaphysical necessity of being, does not bring with it a universal guarantee of objectivity. It can also be accompanied, in concrete knowing, by subjective elements that represent its limits and that only an integral engagement of human spiritual energies is capable of overcoming. It is in this sense that a positive value must be recognized in the criterion of "convergence" recently advocated by A. Brunner. But evidence is, in any case, at the bottom of every certainty of ours, even when it is brought into act not by an intellectual or rational process alone (intuition and demonstration) but together by demands of a not properly cognitive order, such as spiritual experience, feeling, love, action (v. EVIDENZA).

Ugo Viglino