One of the Greatest Blockheads in the World
Seeing the devil is so cunning and subtile, it may seem a paradox, why he will endeavor to frustrate the designs of an omniscient being, or to pretend to counterwork him that is omnipotent, and will not suffer anything but what is for his own glory: seeing that God turns everything he does to the greater and more illustrious advancement of His own honor, and seeing he has experience of it, for so long a time, [that] all his deep laid contrivances have at last come out to his own overthrow, and the event has been directly contrary to his design.
To this I say, that although the devil be exceeding crafty and subtile, yet he is one of the greatest fools and blockheads in the world, as the subtilest of wicked men are. Sin is of such a nature that it strangely infatuates and bewitches persons: makes men deliberately choose eternal torments rather than miss of their pleasure of a few days, and to esteem a little silver and gold above eternal happiness; makes men choose a few minutes pleasure, though eternal flames be joined therewith, rather than not have it—thus do the cunningest of wicked men. Sin has the same effect on the devils, to make them act like fools, and so much the more as it is greater in them than in others.
The devil acts not according to his deliberate judgment, but is driven on to his own inexpressible torment by the fury of sin, malice, revenge and pride; is so entirely under the government of malice, that although he never attempted anything against God but he was disappointed, yet he cannot bear to lie still, and refrain from exerting himself with all his might and subtilty against the interest of holiness; though he, if he considered, might know that it will turn to its advantage.
—Jonathan Edwards, Miscellanies #48 (paragraphing added)