The trouble about argument is that it moves the whole struggle onto the Enemy’s own ground. He can argue too; whereas in really practical propaganda of the kind I am suggesting He has been shown for centuries to be greatly the inferior of Our Father Below.
This excerpt shows Lewis’ conviction that all sound (reasonable) arguments are on the side of God (“The Enemy”), whereas all lies are on the side of “Our Father Below,” as Wormwood affectionately refers to the Devil.
Instead of argument, Screwtape suggests that the real key to success is delusion by refusing to allow their “patient” to actually thoughtfully consider key evidences. One way this is accomplished is by using to their advantage “the part of the man . . . best under my control”, namely the human’s appetites. This device is illustrated by Wormwood from an instance in his own experience. The “patient” was kept from thinking and, says Wormwood “He is now safe in Our Father’s house” (What an incredibly chilling statement!).
Finally, Screwtape urges Wormwood to “remember . . . you are there to fuddle him. From the way some of you young fiends talk, anyone would suppose it was our job to teach!” Here we see that the main objective of the devils is not to argue in the realm of truth, but to delude the minds of their “patients”!