SCEPTICISM (Lat. SCEPTICISMUS, Ital. SCETTICISMO, Fr. SCEPTICISME, Germ. SKEPTIZISMUS, Eng. SCEPTICISM)
Sometimes the terms scepticism and dogmatism are contrasted with one another: religious scepticism, for example, may coexist with rationalistic or scientific dogmatism, and vice versa, a scepticism regarding the possibilities of reason may be associated with extreme forms of religious dogmatism.
It is necessary to distinguish between scepticism as a purely psychological attitude and scepticism as a systematic position. In the first case, scepticism is a simple mental attitude, a doubt in fact, more or less conscious of its own reasons; it may be more or less serious (frivolous, inconstant scepticism) according to the different spiritual value and moral sincerity of the person who professes II. As a systematic position, scepticism presents itself, in its own way, as a (negative) philosophical conception derived from factual and principled premises; it may assume the form of “dogmatic scepticism” if it is expressed in the formula: “it is not possible to have certain theoretical knowledge”; or of simple agnostic negativism if it resolves itself into the affirmation: “it is impossible to affirm or deny; it is doubtful, the value of truth and certainty of knowledge”. Although dogmatic scepticism presents the character of absolute radicalism, there is, however, an essential equivalence between the two positions inasmuch as the doubt, resolute and definitive, regarding the possibilities of certainty involves the negation of certainty itself. Every position which accepts doubt as a non-resolutive but methodological moment, or, in any case, as an attitude of research which does not systematically exclude the possibility of objective certainty, must be distinguished from scepticism (cf. PROBLEMATICISM). Analogous expressions of scepticism are empiricism and phenomenism (cf.): every consistent empiricism cannot but conclude in a general theoretical agnosticism, which is precisely the essence of scepticism.
The causes of the sceptical attitude have been historically diverse. The principal ones to be indicated are: the contradictions of thought and of existence; the obscurity of problems, of reasons and purposes of things; the uncertainty of values in life and in history.
Scepticism had a mature development in Greek philosophy. Partial motives for it can be found in the school of Elea (cf. ELEATISM), which considered the world of the senses as appearance and illusion. A fragment of Xenophanes states: “opinion [as opposed to truth] reigns everywhere”, ὀκόσα τἐτυχται ἐπὶ πᾶσι (G. A. Mullach, I, Paris 1860, p. 103, fr. 14). The Sophists were undoubtedly inclined towards scepticism: such are the assertions of Gorgias regarding the unknowability of being and the impossibility of true communicative discourse (cf. Pseudo-Aristotle, De Xenophane, Zenone et Gorgia, cap. 5) and the saying of Protagoras that of every thing opposite reasons can be given (Diogenes Laertius, IX, 51), an anticipation of the sceptical λογοδέξια. The sceptical school also referred, besides to Heraclitus, Zeno, Parmenides, Anaxagoras, Empedocles, Democritus, etc. (cf. Diogenes Laertius, IX, 71-73; Sextus Empiricus, Phyrrh. hypot., I, 220 ff.; Cicero, Acad., I, 72 ff.), to Socrates and Plato. In reality, the certainty which Socrates had of moral science (the profession of ignorance was not in him scepticism, but a methodological moment of knowledge: cf. Apol., 21 b-d) and the positive dialectic of Plato exclude scepticism. At most, latent motives for it can be found in the unknowability of nature, affirmed by Socrates, and in the significance of appearance attributed by Plato to the world of the senses.
True scepticism proper asserts itself with Pyrrho of Elis (c. 365-270 B.C.; cf. PYRRHONISM). According to Brochard, the scepticism of Pyrrho has a practical character; it does not arise from dialectic but represents a reaction to dialectic; its fundamental idea is: to make of doubt an instrument of wisdom and moderation, of stability and happiness (op. cit. in bibliography, p. 67). It is expressed in the programmatic assertions which later became common to the sceptics: nothing is comprehensible (ἀκαταληψία); therefore one must abstain from assent (ἐποχή); nor can anything be said to be “rather so” (οὐ μᾶλλον); it defines nothing (οὐδὲν ὀφέως); all is hidden (πᾶντα ἀόριστα); nothing is in itself good or bad, just or unjust, and all men do by law and custom (νόμοι δὲ καὶ ἔθεν; cf. Diogenes Laertius, IX, 61). Hence the various denominations of the sceptics: σκεπτικοί, inasmuch as they always look and never find; ζητητικοί, inasmuch as they remain in research; ἀπορητικοί, inasmuch as they doubt; ἐπιστικοὶ (from ἐπέχω), inasmuch as they suspend every judgment (ibid., IX, 69-70). As a consequence of the abstention from judgment, scepticism posited the tranquillity or imperturbability of the soul (ἀταραξία: ibid., IX, 107); impassivity (ἀπαθεία: ibid., 108) and indifference (ἀδιαφορία: ibid., IX, 109). For Pyrrhonism, the uncertainty and relativity of perception and the impossibility of absolute demonstration are attitudes of scepticism, inasmuch as the validity of demonstration supposes a criterion, and the criterion in turn needs a demonstration (ibid., 79 ff.). Absolute scepticism, therefore, regarding every definition of the nature of things: “As men we affirm the things which present themselves to us; that it is day, that we live and many other things which present themselves (προνοῦμενων) in our life, we know; but regarding those things which the dogmatics affirm to understand by reason, we suspend our assent because we consider them uncertain and obscure; and we only recognize our affections” (μὴ νὰ ἐὰ τὰ πάντα γινόσκοντες: ibid., 103): a testimony which supports the assertion of Richter (op. cit. in bibliography, I, p. 108 ff.), that there is in Pyrrhonism an anticipation of human scepticism, apart from, in English scepticism, the subjectivistic moment, absent from ancient scepticism, which questions the very existence of reality beyond phenomena. The most distinguished among the immediate disciples of Pyrrho was Timon of Phlius (b. 325 B.C., d. in Athens 235 B.C.), of whose many works only a few fragments remain. Later, Pyrrhonism was taken up again by Aenesidemus of Cnossus (Crete; the date of birth is uncertain: between 80 B.C. and 130 A.D.); and by Agrippa (mentioned in Diogenes Laertius, but of whom nothing is known: Hass is of the opinion that he taught towards the end of the 1st century B.C.). To Aenesidemus (whose Παρχών: Ἀνθρωποι λόγοι, besides the Περὶ σοφίας, and the Περὶ ζητήσεως are lost) are attributed the ten “tropes” (τὸ περὶ, τῷ περὶ, λόγοι) or reasons for abstaining from assent, handed down, with slight variations, by Diogenes Laertius and Sextus: the perception and representations vary according to: 1) the diversity of animals; 2) the differences found in men; 3) the different constitution of the senses; 4) circumstances; 5) position, distance, place; 6) the mixtures of objects; 7) their quantity and composition; 8) their relations; 9) their frequency or rarity; 10) institutions, customs, laws, fabulous beliefs and dogmatic opinions (Sextus, Phyrrh. hypot., I, 36 ff.; Diogenes Laertius, IX, 79 ff.). Equally remembered are the five “modes” of Agrippa: 1) the discordance of men; 2) the infinite process in demonstration; 3) the variety of objects according to their relations; 4) hypothesis, when, to avoid the infinite process in demonstration, a hypothetical principle is assumed as certain; 5) the vicious circle (ἐξαλλαγὴ πρὸς τοὺς περὶ), when what needs to be proved by the conclusion is taken as a premise (Sextus, Phyrrh. hypot., I, 164 ff.; Diogenes Laertius, IX, 88-90).
But even before the restoration of Pyrrhonism by Aenesidemus, scepticism had been embraced by the New Platonic Academy with Arcesilaus (the Ciceronian tradition, followed by Brochard [op. cit. in bibl., p. 29], posited only two Academies: the old one of Plato and the new one of Arcesilaus; Sextus [Phyrrh. hyp., I, 220 ff.] gives Carneades’ school as a third and reports that others distinguished two further later Academies). Arcesilaus of Pitane (c. 315–240 BC) was almost a contemporary of Pyrrho, but, it seems, independent of him (Hirzel, Natorp; cf. Credaro, op. cit. in bibl., I, pp. 130 ff.): the scepticism he introduced into the Academy was essentially dialectical, inasmuch as it involved systematic analysis and critique of Stoic and Epicurean doctrines (ibid., II, pp. 229–30). Against the Stoic claim to καταληψία “comprehension,” Arcesilaus declared that no perception contains within itself a guarantee of truth: there is no representation that is truly “perceptive,” and opposing arguments prevent assent regarding everything: “Arcesilaus negabat esse quidquam quod sciri posset...; sic omnia latere censebat in occulto; neque esse quidquam quod cerni aut intelligi posset” (Cicero, Acad., I, 45; cf. Diogenes Laertius, IV, 28 ff.). Nevertheless, since in practice a criterion is needed to guide action, “he who universally suspends judgment (περὶ παντός) will conform his doing and not doing to what is reasonable (τῷ εὐλογῷ; cf. Sextus, Adv. math., VII, 158).” Arcesilaus’ εὐλογον is therefore (Hirzel, Credaro) a purely practical norm: it is the reasonableness of action in relation to its eudaimonistic end, and prudence, a sense of propriety, the art of living well—thus lacking any theoretical significance.
After Arcesilaus’ immediate successors—Lacyde of Cyrene, Hegesinus of Pergamon, Evander—the Academy continued in the direction he had set under Carneades of Cyrene (c. 219(14)–129(28) BC), “homo omnium in dicendo acerrimus et copiosissimus” (Cicero, De orat., I, 45). Carneades (who wrote nothing, his doctrine being transmitted by his disciples) took up a thoroughgoing critique of Stoic dogmatism (especially that of Chrysippus: “If Chrysippus had not existed, neither would I”; Diogenes Laertius, IV, 62). There is no criterion of truth in reason or in the senses: reasoning, representation, and sensation are sources of illusion and error. Knowledge of things in themselves (πρὸς τὴν φύσιν) is therefore impossible: whether the gods exist, whether the world is their work or governed by them, cannot be known; the wise person neither affirms nor denies but suspends judgment. The same must be said of ethics: moral evaluations are not grounded in absolute norms but are mere opinions, varying with men and times (cf. Cicero, De leg., I, 42). Yet for Carneades there are representations that, in relation to man and his nature, appear true and thus possess, in varying degrees, probability (πρὸς τὴν φύσιν); this probability is adopted as a criterion of practical truth: a representation that is plausible, not contradicted by others, well tested, affords the highest degree of persuasion and serves as the criterion for the sage’s deliberation (cf. Sextus, Adv. math., I, 166–89; Phyrrh. hyp., I, 226–31). Carneades’ πρὸς τὴν φύσιν (which earned his school the label “probabilism”) is something more than Arcesilaus’ εὐλογον, since it concerns the credibility or admissibility of a proposition; yet because likelihood is relative to the subject, it does not seem to represent an actual overcoming of scepticism (cf. Credaro, op. cit. in bibl., II, pp. 68 ff.). The teachings of Carneades were collected by his pupil and successor Clitomachus of Carthage; later, the Academy turned back toward Platonism (as seen in Cicero and Sextus).
Sextus Empiricus ([v.]) belongs to the school of the “empirics”: physician-philosophers who opposed dialectic with art, observation, experience, and medicine (represented, between the second half of the 2nd century AD and the beginning of the 3rd—he himself probably born c. AD 80—was the last great Greek exponent of this school, though his origins are unknown and certainly not Athenian or Alexandrian). The works that survive from him (Outlines of Pyrrhonism, Πυρρὸν νοῦν τοὺς πίστεως [Italian trans. by O. Tescari, Schizzi pirroniani, Bari 1926]; Against the Mathematicians, Πρὸς μαθηματικοὺς; Against the Dogmatists, Πρὸς δογματινοὺς; the last two usually combined under the title Adversus mathematicos) are the most valuable source for scepticism. In them Sextus gathers, organizes, and develops into a systematic exposition, clear and detailed, all the arguments and doctrines of the ancient sceptics; it is therefore impossible to determine what belongs to him personally. The essential human significance of scepticism, for Sextus, may be summed up in the following words: “We do not intend to oppose common assertions nor to remain inactive...” (Adv. math., VIII, 157). “It is enough, I think, to live according to experience and without dogmas, in conformity with ordinary observations...,” suspending judgment on matters raised by dialectical subtlety that lie entirely outside what is useful for life (Phyrrh. hyp., II, 246; cf. I, 19 ff.).
Christian thought, with its certainty of Revelation ([v.]), stands opposed to scepticism. Yet partially sceptical motifs do appear at times in the underestimation of rational-philosophical knowledge in comparison with faith (cf. Lactantius, Div. inst., I, 2: PL 6, 117–18; III, 4: ibid., 357–58). St Augustine had at first inclined toward Academic scepticism: “academicorum more dubitans de omnibus atque inter omnia fluctuans” (Conf., V, 14); later, in the Contra acad. and elsewhere, he marshalled against scepticism the certainty that doubt and the truth it contains entail (cf. Contra acad., III, 9; De Trin., XV, 12; De civ. Dei, XI, 26; De vera relig., 36, 73). In its entirety, medieval scholasticism (apart from the tendency toward theological agnosticism expressed in the so-called “negative theology,” which, however, by reason of its pronounced mystical character, had essentially a positive meaning) was a rejection of scepticism. The principal source of scepticism, Sextus’ Hypotyposes, does not seem to have been unknown to the scholastics: a Latin translation was indeed discovered in the library of St Victor in 1888 by Picavet and again in 1891 by Baumker (Eine bisher unbekannte mittelalter. lateinische Uebersetz. des Hyp. V. Sextus Emp., in Arch. f. die Gesch. d. Philos., 4 [1891], pp. 574–77). Skeptical assertions, especially regarding knowledge of causality in creatures and the existence of the external world, occur in Nicholas of Autrecourt ([v.]): in 1347, among other propositions, the following were condemned by Clement VI: “Quod de rebus per apparentia naturalia nulla certitudo haberi potest”; “Quod de substantia materiali alia ab anima nostra non habemus certitudinem exsistentiae”; “Quod nescimus evidenter quod aliqua causa efficiens naturalis sit vel esse possit” (Denz.-U., 553–70).
BIBL.:
Brochard, Les sceptiques grecs, Paris 1887.
Credaro, Lo scetticismo degli Accademici, Milano 1893.
Hirzel, Untersuchungen zu Ciceros philosophischen Schriften, Leipzig 1877–83.
Picavet, Les traductions latines de Sextus Empiricus, in Rev. de philol., 1888, pp. 129–38.
Baumker, Eine bisher unbekannte mittelalter. lateinische Uebersetz. des Hyp. V. Sextus Emp., in Arch. f. Gesch. d. Philos., 4 (1891), pp. 574–77.
Denz.-U., Enchiridion symbolorum, ed. 20a, Freiburg 1937.
The ancient forms of skepticism are taken up again in the 16th century by Montaigne (q.v.): the various solutions offered by philosophical dogmatism to the eternal problems of being, the soul, and God do not allow for a reasonable choice; not even plausibility can be accepted, since its determination presupposes a knowledge of the truth. The grounds for skepticism lie in the relativity of sensory knowledge, the source of all our knowledge, and in the inevitable circularity of demonstration. It is better, therefore, to suspend all judgment on the nature of things and of ourselves and to rely on the guidance of experience and faith, without demanding from faith a rational demonstration (cf. *Essais*, II, ch. 12; III, ch. 8, 13). From Montaigne derives the position of P. Charron ([q.v.] *Le traité de la sagesse*, Bordeaux 1601), who reaffirms in the face of reason the foundation and necessity of faith. Similar motifs are found in Fr. Sanchez ([1562–1632] *Tractatus de multum nobili et prima universali scientia quod nihil scitur*, Lyon 1581: Sanchez’s position was primarily polemical against the science of his time).
In the 17th century, skepticism is revived by S. Foucher ([1644–96] *Lettres par un académicien*, Paris 1675; *Apologie des académiciens*, 1687). Of Pascal (q.v.), his expressions on the impotence of reason are well known (“la raison impuissante”; “nous sentons une image de la vérité et ne possédons que le mensonge”: *Pensées*, 434, ed. Brunschvicg, Paris 1949, p. 229); but their meaning lies rather in a confession of man’s inability to realize his existence and spiritual destiny without the aid of grace. Nor is there any doubt in Pascal as to the fundamental value of human nature: “je met en fait qu’il n’y a jamais eu de pyrrhonien effectif parfait” (ibid.; cf. also 83, pp. 86–87 and 374, p. 201).
In modern philosophy, the most elaborate expression of skepticism in a metaphysical sense is human phenomenism (q.v.). The value of knowledge and reason, which Hume does not intend to reject with an absolute negation of “excessive” skepticism (Hume does not call himself a skeptic), is nonetheless rigorously confined within the sphere of facts, experience, and abstract quantitative relations (mathematics). Every attempt by reason beyond these limits (metaphysics, theology, the search for causes) is nothing but “sophistry and illusion” (*Enquiries*, sect. 12a, part 3, ed. Selby-Bigge, no. 132, Oxford 1951, p. 165; cf. the interaction). Hume’s subtle critique, as is well known, influenced Kant and, through Kant, later epistemologies (against the alleged Kantian overcoming of skepticism, it was reaffirmed by G. E. Schultze [q.v.] in the *Aenesidemus*, Helmstedt 1792). Skepticism was not generally taken up again in the negative absolutism of its ancient formulation (which had already been systematically concluded with Greek skepticism); but alongside grandly constructive systems (e.g., idealism), the most radical instances of skepticism have remained alive in recent and contemporary philosophical thought. The task pursued by criticism and later speculative effort—to determine the possibilities and limits of reason—has ultimately resulted, sometimes through positive solutions themselves, in explicit renunciations of metaphysics (positivism, agnosticism, pragmatism, neopositivism, existentialism). Recently in Italy, a defense of skepticism has been proposed by G. Rensi (q.v.): skepticism, as the uncertainty of every solution to metaphysical problems, is the only sincere position for thought: “in the moment in which [the philosopher] thinks about a metaphysical problem, he cannot but perceive, indeed feel deeply, how the opposing solutions are equally possible” (*Sic et non*, Rome 1911, p. 11).
Against skepticism, it has always been objected that it involves an internal contradiction in absolutely denying the truth: whoever claims to know nothing at least knows that he does not know, and whoever says that all judgment must be suspended is making a judgment: “si nihil sciri potest, necesse est id ipsum sciri, quod nihil sciatur... Sic inducitur dogma sibi ipsi repugnans, seque dissolvens” (Lactantius, *Div. inst.*, III, ch. 6: PL 6, 361). The nature of thought, which is essentially affirmation, does not permit a truly universal doubt; thought in act is always, in some sense, certainty: “si dubitat, dubitare se intelligi; si dubitat, certus esse vult; si dubitat, cogitari; si dubitat, sciri se nescire; si dubitat, iudicat non se temere consentire oportere” (St. Augustine, *De Trinit.*, X, ch. 10, no. 14: PL 42, 981). While this critique of skepticism rightly highlights the intrinsic inconsistency of an absolute denial of certainty, it does not, however, address the most authentic instances of historical skepticism, which does not contest all certainty but only that which claims to extend beyond facts and experience. One may agree with Hume that “no one has ever met with a person who had no opinion or principle on any subject, whether practical or speculative” (*Enquiries*, sect. 12a, part 1, ed. cit., no. 116, p. 148). The consideration that skepticism demands (“despite appearances, Pyrrho, Carneades, Aenesidemus, Agrippa have well deserved of the human spirit”: Brochard, op. cit. in bibl., p. 130) is elsewhere: in its appeal to the essential dimension of the inadequacy of human possession of the truth. There is no consciousness (whether it turns to the metaphysical depths of the world, the self, will, freedom, or action) that does not encounter a limit and opposition, a content that is always a further deferral and resists absolute, conclusive, exhaustive grasp by thought. This condition, which is the gravest mystery of man in search of truth and not assured in his possession of it—whether theoretically or practically—is a limit always present to the possible excesses of philosophical dogmatism. But skepticism is wrong not to recognize the universality and immutability of the value that truth—even ordinary truth—presents to human consciousness and thought. Hypothesis, probability, doubt, and error certainly accompany, as moments in its becoming, every effort of thought: the ὁμολογεῖν τὸν λόγον is often a reality in knowledge and life. Yet it is precisely these—hypothesis, probability, doubt, and error—that measure us in relation to the truth, which, even if it remains for man only an ideal term, nonetheless structures his mind, thought, and action. Man is in the truth, fundamentally, through his very thinking, just as he is fundamentally in being, even if both truth and being are not subject to his absolute dominion—as a creature. And the criterion of truth contested by skepticism is something man possesses in his very intellect as an expression, however participated and limited, of being and its fundamental meanings (logical, real, moral), and thus also as an initial possibility for metaphysics. The very fact that we can discern, discover, and abandon error confirms that we generally possess a norm of certainty. The relativity of sensory knowledge and the variety of human opinions cannot be arguments for skepticism; they only confirm that knowledge has a margin of contingency and historicity—expressed for each person by his particular individual situation in time. To the Pyrrhonian instances regarding sensory perception, the answer is not difficult through a critique of perception itself that clarifies its subjective modalities and contains its meaning of truth within the terms of an objective but conditioned relation of reality to the subject.
The moral optimism (ἐπισχέζει) that ancient tradition posited as a consequence of its negative theoretical stance is by no means a necessary derivation. A situation of radical uncertainty regarding the meaning of existence, for a conscience that seeks itself with complete sincerity, is rather a cause of obscure unease, as well as a negative element for the spiritual commitment of life and action.