Logic is a large drawer, containing some useful instruments, and many more that are superfluous. A wise man will look into it for two purposes, to avail himself of those instruments that are really useful, and to admire the ingenuity with which those that are not so, are assorted and arranged. – Charles Caleb Colton, Lacon

The last function of reason is to recognize that there are an infinity of things which surpass it. – Blaise Pascal, Pensées, 1670

Reason: The arithmetic of the emotions. – Elbert Hubbard, The Roycroft Dictionary

But, logic, like whiskey, loses its beneficial effect when taken in too large quantities. – Edward John Moreton Drax Plunkett Dunsany, "Weeds & Moss," My Irelan