FOLLY AND FOOL (in Biblical Hebrew, "kesil," "kislut," or "ewil," "iwwelet"; Neo-Hebraic "shoṭeh," "sheṭut" ["nabal," "nebalah," however, do not signify "fool," "folly," as in A. V. (Ps. xiv. 1, liii. 1, lxxiv. 18; Isa. xxxii. 6; Gen. xxxiv. 7; Deut. xxii. 21, xxxii. 6; Judges xx. 6; Jer. xxix. 23), but "a vile man," "villainy"]):
According to the Jewish conception, folly is the antithesis of morality and piety (Prov. xiii. 19; Job xxviii. 28), as well as of wisdom and prudence (Prov. xiii. 16, 20); and the fool is an offender against religion and ethics, and a hater of knowledge (Prov. i. 7, 22). In fact, the fool is the subject of such frequent rebuke in the Wisdom literature chiefly because his folly leads to an untimely end (Prov. x. 14; Eccl. vii. 17), brings unhappiness to others (Prov. x. 1, xvii. 25), creates evil habits (Prov. x. 23) and bad traits (Prov. xv. 5, xvii. 10), and causes sin (Ps. lxix. 6; Prov. xxiv. 9; Jer. v. 21) and a misconception of divine providence (Ps. xcii. 7, 8). Folly promotes insolence (Prov. xiv. 16), conceit (Prov. xii. 15), irreverence (Prov. xv. 20), contentiousness (Prov. xviii. 6), anger (Prov. xxvii. 3), extravagance (Prov. xxi. 20), and sensuality (Prov. x. 23).
To prevent folly and to correct it, the use of the rod was recommended (Prov. xxii. 15, xxvi. 3). The Rabbis also emphasized the ethical side of folly. R. Joshua sees danger for society when piety is linked to folly (Soṭah iii. 4), and Resh Laḳish maintains that "a man sins only when the spirit of folly enters into him" (Soṭah 3a; compare Maimonides, "Moreh," iii. 11). In rabbinical parables reference is frequently made to the fool. R. Johanan b. Zakkai likens those who are unprepared for death to fools who are not ready for the banquet when suddenly summoned by the king (Shab. 153a; compare Matt. xxv. 1-14).