Rather than denoting a person who is lacking in mental ability, the word “fool,” as used in the Bible, generally refers to an individual who spurns reason and follows a morally insensible course out of harmony with God’s righteous standards. Various Hebrew terms denoting such a one are kesilʹ (‘stupid one’; Pr 1:22), ʼewilʹ (“foolish one”; Pr 12:15), na·valʹ (‘senseless one’; Pr 17:7), and lets (“ridiculer”; Pr 13:1). The Greek aʹphron refers to an “unreasonable one” (Lu 12:20), a·noʹe·tos to one “senseless” (Ga 3:1), and mo·rosʹ to a ‘fool’ or “foolish” one (Mt 23:17; 25:2).
Answering a fool in harmony with or “according to his foolishness” in the sense of resorting to his degrading methods of argument puts the one so doing in agreement with the fool’s unsound reasonings or ways. In order not to become like the fool in this respect, we are counseled by the proverb: “Do not answer anyone stupid according to his foolishness.” On the other hand, Proverbs 26:4, 5 shows that answering him “according to his foolishness” in the sense of analyzing his contentions, exposing them as being ridiculous, and showing that his own arguments lead to entirely different conclusions from those he has drawn can be beneficial.