foolish, senseless: lacking the sound sense that comes from reckoning with God, so that a person's thinking and living both go wrong
The word is built from a negative prefix on the Greek term for the mind or wits, so at root it means "without wits, senseless." In ordinary Greek it was the opposite of the sensible, prudent person, and could describe anything from reckless behavior to plain dullness. But the New Testament writers inherit it through the Greek Old Testament, where translators chose it to render Israel's sharpest words for the fool (נבל, כסיל). That choice loaded the word with a moral and religious weight it did not carry in classical Greek.
In the Bible the fool is not the person with a low IQ. He is the person who lives as though God were not a factor. The pattern verse is the one that says, "The fool has said in his heart, there is no God" (Psalm 14:1), and the classic portrait is the rich man in Jesus' parable who plans his whole future in a speech that never once mentions God, only to lose his life that very night. To be this kind of fool is to miscalculate about reality itself, because the God the fool leaves out is the largest fact there is.
Because Israel's wisdom tradition treated clear thinking and right living as inseparable, one word covers both a failure of the mind and a failure of the heart. That is why it can rebuke someone for not reasoning rightly, as Paul does to an imagined objector who cannot see how a buried seed pictures resurrection, and in the same breath name the deeper folly of a life with no room for God. Paul also turns the word on himself: forced to defend his ministry by boasting, he plays the part of the fool, wearing the label as an ironic mask to expose the real foolishness of his rivals.
Nuances
How to read Paul's calling himself a fool throughout his boast in 2 Corinthians 11 and 12. Scholars agree he deliberately takes on the role of the fool; they divide over what the role is doing.
- majorityIt is mainly ironic parody: Paul apes the self-praise of his rivals in order to expose them as the real fools.; H. D. Betz, Der Apostel Paulus und die sokratische Tradition (BHT 45; Mohr, 1972), 74-89; Christopher Forbes, 'Comparison, Self-Praise and Irony,' New Testament Studies 32 (1986): 1-30
- minorityIt follows a recognized convention that let a person under attack praise himself if he mixed in admissions of weakness and gave the credit to God.; Peter Marshall, Enmity in Corinth (WUNT 2/23; Mohr, 1987); Laurent Pernot, 'Periautologia,' Revue des Etudes Grecques 111 (1998): 101-24
- minorityIt registers Paul's genuine discomfort at boasting, not merely a rhetorical device.; Ralph P. Martin, 2 Corinthians (WBC 40; rev. ed.; Nelson, 2014); Paul Barnett, The Second Epistle to the Corinthians (NICNT; Eerdmans, 1997), 507-08
Disputed
How much of the word's biblical meaning is moral and religious, the fool who lives without God, rather than simply intellectual, a person who lacks sense.
- majorityIn biblical Greek the word carries the full moral and religious weight of the Old Testament fool who leaves God out; the translators who rendered Israel's fool-words with it reshaped its meaning.; Georg Bertram, 'phren, aphron, aphrosyne,' TDNT 9:220-235; Johann Cook, The Septuagint of Proverbs (VTSup 69; Brill, 1997); T. Muraoka, A Greek-English Lexicon of the Septuagint (Peeters, 2009), s.v.
- minorityThe word remains chiefly a term for intellectual senselessness; its Old Testament coloring is a byproduct of stereotyped translation and should not be over-read.; A. Pietersma and B. G. Wright, eds., A New English Translation of the Septuagint (Oxford, 2007); LSJ, s.v. aphron