Mental derangement, either insanity or a condition of extreme rage or great folly. Various Hebrew and Greek words are employed in the Scriptures to denote such disorders of the mind, whether lasting or temporary. Some of these words seem to be associated with or derived from the weird and sometimes violent or sorrowful cries of persons afflicted with madness.

Madness befell boastful Babylonian King Nebuchadnezzar. In fulfillment of a prophetic dream explained by Daniel, this monarch was stricken with madness at a time of boasting. For seven years he was insane, “and vegetation he began to eat just like bulls.” (Da 4:33) His reason gone, Nebuchadnezzar may have imagined that he was a beast, perhaps a bull. Regarding his mental derangement, a French medical dictionary states: “LYCANTHROPY . . . from [lyʹkos], lupus, wolf; [anʹthro·pos], homo, man. This name was given to the sickness of people who believe themselves to be changed into an animal, and who imitate the voice or cries, the shapes or manners of that animal. These individuals usually imagine themselves transformed into a wolf, a dog or a cat; sometimes also into a bull, as in the case of Nebuchadnezzar.” (Dictionnaire des sciences médicales, par une société de médecins et de chirurgiens, Paris, 1818, Vol. 29, p. 246) At the end of the seven years, Jehovah restored Nebuchadnezzar’s understanding to him.​—Da 4:34-37.

Madness and Demon Possession. While not all persons afflicted with madness or insanity are possessed by the demons, logically persons possessed by the demons may be expected to manifest an unbalanced mental state. In the country of the Gerasenes, Jesus encountered a madman who was demon possessed. His haunt was among the tombs, and though he had often been bound with fetters and chains, “the chains were snapped apart by him and the fetters were actually smashed; and nobody had the strength to subdue him.” Further, “continually, night and day, he was crying out in the tombs and in the mountains and slashing himself with stones.” After Jesus cast out the demons, the man had a “sound mind.” (Mr 5:1-17; Lu 8:26-39) However, Christians are kept safe from demon invasion that produces madness if they put on and keep on “the complete suit of armor from God.”​—Eph 6:10-17.

Feigned Madness. On one occasion, while he was outlawed by King Saul, David sought refuge with Achish the king of Gath. Upon discovering who he was, the Philistines suggested to Achish that David was a security risk, and David became afraid. Consequently, he disguised his sanity by acting insane. He “kept making cross marks on the doors of the gate and let his saliva run down upon his beard.” Thinking David was crazy, Achish let him go with his life, as a harmless idiot. David was later inspired to write Psalm 34, in which he thanked Jehovah for blessing this strategy and delivering him.​—1Sa 21:10–22:1.

Madness of Opposition to Jehovah. The prophet Balaam foolishly wanted to prophesy against Israel in order to receive money from King Balak of the Moabites, but Jehovah overruled and prevented his efforts. The apostle Peter wrote about Balaam that “a voiceless beast of burden, making utterance with the voice of a man, hindered the prophet’s mad course.” For Balaam’s madness the apostle used the Greek word pa·ra·phro·niʹa, which has the thought of “being beside one’s mind.”​—2Pe 2:15, 16; Nu 22:26-31.

Regarding the false prophets of Israel, the prophet Hosea wrote: “The prophet will be foolish, the man of inspired expression will be maddened on account of the abundance of your error, even animosity being abundant.” (Ho 9:7) Jehovah brings madness to his opposers and those who reject his wisdom, identifying himself as “the One that makes diviners themselves act crazily,” that is, by making their forecasts prove false. (Isa 44:24, 25) Job said, concerning worldly judges, that Jehovah “makes judges themselves go crazy.”​—Job 12:17.

Paul compared men who resisted the truth and who tried to corrupt the Christian congregation to Jannes and Jambres, who resisted Moses. He assured: “They will make no further progress, for their madness will be very plain to all, even as the madness of those two men became.”​—2Ti 3:8, 9.

Madness From Oppression and Confusion. Among the dire consequences the Israelites would suffer for disobedience to Jehovah was being stricken with madness. As a result of the oppressive measures of their conquerors, they would become maddened, responding in an unreasoning way because of frustration. (De 28:28-34) Indeed, King Solomon stated that “mere oppression may make a wise one act crazy.”​—Ec 7:7.

 In prophecy Babylonian King Nebuchadnezzar was likened to the ‘cup of the wine of Jehovah’s rage.’ This the nations would have to drink, and it would cause them to “shake back and forth and act like crazed men because of the sword that I [Jehovah] am sending among them.” (Jer 25:15, 16) Later, in Babylon herself madness would be brought about, her idolaters having horrifying visions, “and because of their frightful visions they [would] keep acting crazy.” (Jer 50:35-38) She, too, would have to drink the cup of Jehovah’s rage.​—Jer 51:6-8.

Extreme Rage. Madness, as used Biblically, can also denote extreme rage. On a sabbath day Jesus cured a man with a withered right hand. The observing scribes and Pharisees thereupon “became filled with madness, and they began to talk over with one another what they might do to Jesus.” (Lu 6:6-11) To describe their state of mind, Luke used the Greek word aʹnoi·a, meaning, literally, “mindlessness” (the English word “paranoia” is related to this term). Paul evidently had in mind extreme rage or fury when he admitted that in persecuting Christians he had been “extremely mad against them.”​—Ac 26:11.

Contrasted With Wisdom. In the book of Ecclesiastes, the congregator reveals that he gave his heart “to knowing wisdom and to knowing madness.” (Ec 1:17) His investigation did not restrict itself to considering wisdom but also took into account its opposite as manifested by men. (Ec 7:25) At Ecclesiastes 2:12, Solomon again reveals that he weighed wisdom, madness, and folly. In this way he could determine their contrast in value. He recognized inordinate frivolity as madness, saying, “I said to laughter: ‘Insanity!’” for, as compared with wisdom, it was senseless, not producing real happiness.​—Ec 2:2.

Commenting on the stupid one’s condition of mind, Solomon said: “The start of the words of his mouth is foolishness, and the end afterward of his mouth is calamitous madness.” (Ec 10:13) Foolishness may take the form of a trick, which can sometimes be so harmful to its victim that the player of the trick is likened to a madman armed with deadly weapons.​—Pr 26:18, 19.

Some have no hope in the resurrection of the dead, thinking that death ends all for everyone. Giving evidence of their unbalanced outlook, they seek only to satisfy their fleshly inclinations and show no concern about doing God’s will. Solomon also took note of them, saying: “Because there is one eventuality to all, the heart of the sons of men is also full of bad; and there is madness in their heart during their lifetime, and after it​—to the dead ones!”​—Ec 9:3.

Illustrative Use. The apostle Paul’s authority and apostleship were challenged by some in Corinth whom he sarcastically termed “superfine apostles.” (2Co 11:5) In order to bring the Corinthian congregation to their senses, Paul “boasted” about his credentials, his blessings and the things he had experienced in Jehovah’s service, proving his claim. This boasting was contrary to the usual speech of a Christian, but Paul had to do it in this case. Hence he spoke of himself as though being ‘out of his mind’ and said of the so-called superfine apostles: “Are they ministers of Christ? I reply like a madman, I am more outstandingly one.”​—2Co 11:21-27.