To begin with, if I ask how it is proved that the presence of a free will in man is signified or implied every time it is said, “If thou wilt, if thou shalt do, if thou shalt hear,” Reason will say, “Because the nature of words and the use of language among men seem to require it.” She thus measures divine things and words by the usage and concerns of men; and what can be more perverse than this, seeing that the former are heavenly and the latter earthly? So the stupid thing betrays herself, showing how she has nothing but human thoughts about God. But what if I prove that the nature of words and the use of language even among men is not always such as to make a laughingstock of those who are impotent whenever they are told: “If thou wilt, if thou shalt do, if thou shalt hear”? How often do parents have a game with their children by telling them to come to them, or to do this or that, simply for the sake of showing them how unable they are, and compelling them to call for the help of the parents’ hand! How often does a good doctor order a self-confident patient to do or stop doing things that are either impossible or painful to him, so as to bring him through his own experience to an awareness of his illness or weakness, to which he could not lead him by any other means? And what is more frequent than words of insult and provocation when we want to show either friends or enemies what they can and cannot do?
I mention these things merely in order to show Reason how foolish she is in tacking her inferences onto the Scriptures, and how blind she is not to see that they are not always applicable even with regard to human speech and action, for if she sees a thing happen once or twice, she immediately jumps to the conclusion that it happens quite generally and with regard to all the words of God and men, making a universal out of a particular in the usual manner of her wisdom.
The Bondage of the Will
Luther’s Works Vol. 33