“The wise through excess of wisdom is made a fool.”

Source Book in Ancient Philosophy (1907), The Golden Sayings of Democritus

The Fourfold Treasure (1871) No. 991 http://www.spurgeon.org/sermons/0991.htm

Il était passionné et se croyait sage; j'étais folle, mais je m'en doutais, et, sous ce point de vue, j'étais plus près que lui de la Sagesse.
Maximes et Pensées, #562
Maxims and Considerations

Lest Fools Should Fail
Grooks

Book III, Ch. 8
This quote is a paraphrase of a lengthier statement, as follows: We ordinarily see, in the actions of the world, that Fortune, to shew us her power in all things, and who takes a pride in abating our presumption, seeing she could not make fools wise, has made them fortunate in emulation of virtue; and most favours those operations the web of which is most purely her own; whence it is that the simplest amongst us bring to pass great business, both public and private; and, as Seiramnes, the Persian, answered those who wondered that his affairs succeeded so ill, considering that his deliberations were so wise, ‘that he was sole master of his designs, but success was wholly in the power of fortune’; these may answer the same, but with a contrary turn.
From Essays of Michel de Montaigne, translated by Charles Cotton (1877), Book the Third, Chapter VIII — Of The Art Of Conference. Note : this is the version found at Project Gutenberg.
Attributed

Life of Marcus Cato
Bartlett's Familiar Quotations, 10th ed. (1919)

Part I, ch. 1.
The Compleat Angler (1653-1655)

“Where Desert Spirits Crowd the Night”, p. 264
The Ivory and the Horn (1996)