G.K. Chesterton on Sanity and Reason

Last week I promised a favorite quote of mine from the writings of G.K. Chesteron. I came across the following quote in Brian McLaren's book, A Generous Orthodoxy, on page 67, in the chapter titled "Why I Am Mystical/Poetic." I found Chesterton's words to be both greatly amusing, and at the same time surprisingly profound. He writes:

Imagination does not breed insanity. Exactly what does breed insanity is reason. Poets do not go mad; but chess players do...Perhaps the strongest case of all is this: that only one great English poet went mad, Cowper. And he was definitely driven mad by logic, by the ugly and alien logic of predestination. Poetry was not the disease, but the medicine...He was damned by John Calvin...Poetry is sane because it floats easily in an infinite sea; reason seeks to cross the infinite sea, and so make it finite. The result is mental exhaustion...The poet only asks to get his head into the heavens. It is the logician who seeks to get the heavens into his head. And it is his head that splits...The madman is not the man who has lost his reason. The madman is the man who has lost everything except his reason...Materialists and madmen never have doubts...Mysticism keeps men sane. As long as you have the mystery you have health; when you destroy mystery you create morbidity.