Ecclesiastes 1:17

And I gave my heart to know wisdom, and to know madness and folly: I perceived that this also is vexation of spirit.

And I gave my heart to know wisdom,.... Which is repeated, for the confirmation of it, from Ecclesiastes 1:13, and that it might be taken notice of how assiduous and diligent he had been in acquiring it; a circumstance not to be overlooked;

and to know madness and folly: that he might the better know wisdom, and learn the difference between the one and the other, since opposites illustrate each other; and that he might shun madness and folly, and the ways thereof, and expose the actions of mad and foolish men: so Plato {s} says, ignorance is a disease, of which there are two kinds, madness and folly. The Targum, Septuagint, and all the Oriental versions, interpret the last word, translated "folly", by understanding, knowledge, and prudence; which seems to be right, since Solomon speaks of nothing afterwards, as vexation and grief to him, but wisdom and knowledge: and I would therefore read the clause in connection with the preceding, thus, "and the knowledge of things boasted of", vain glorious knowledge; "and prudence", or what may be called craftiness and cunning; or what the apostle calls "science falsely so called", 1 Timothy 6:20; see Proverbs 12:8;

I perceived that this also is vexation of spirit;

See Gill on "Ecclesiastes 1:14"; the reason follows.

{s} In Timaeo, p. 1084.