Great Wits to Madness nearly are Allied. (Pope.)
Seneca says, “Nullum magnum ingenium absque mixtura dementiœ est.”
Seneca says, “Nullum magnum ingenium absque mixtura dementiœ est.”
Entry taken from Dictionary of Phrase and Fable, edited by the Rev. E. Cobham Brewer, LL.D. and revised in 1895.