This is the doctrine of free will, so much declaimed against in the world, and yet so simple. It had been the doctrine of the church. But the schoolmen had explained it in a manner which caused it to be misunderstood. "No doubt," said they, "the natural will of man cannot do any thing which is truly pleasing to God; but it can do much to render man more capable and more worthy of receiving divine grace." These preparatives they termed merit of congruity;[79] "because," as St. Thomas expressed it, "it is congruous for God to bestow peculiar favour on those who make a good use of their will." In regard, again, to the conversion which man must undergo, it is no doubt true that, according to the schoolmen, the grace of God behoved to accomplish it, but still without excluding his natural powers. "These powers," said they, "have not been annihilated by sin; sin only puts an obstacle in the way of their development; but as soon as this obstacle is removed (and this, according to them, was what the grace of God had to do,) these powers begin again to act." To use one of their favourite comparisons--"the bird whose legs are tied does not thereby lose either its powers, or forget the art of flying, though it must be loosed by some other hand before it can be able again to use its wings." "The same," said they, "is the case with man."[80] [79] Meritum congruum. [80] Planck, i, p. 176. [Sidenote: FREE WILL. ITS TRUE NATURE.] Such was the question discussed between Eck and Carlstadt. At first Eck seemed to deny Carlstadt's propositions out and out, but feeling the difficulty of maintaining his ground, said, "I grant that the will has not power to do a good work, but receives it from God." "Confess then," rejoined Carlstadt, overjoyed at obtaining such a concession, "that every good work comes entirely from God." "Every good work comes indeed from God," replied the schoolman subtlely, "but not entirely." "There," exclaimed Melancthon, "goes a discovery well worthy of theological science." "An apple," added Eck, "is all produced by the sun, but not altogether, and without the co-operation of the tree."[81] Assuredly no man ever thought of maintaining that an apple is all produced by the sun. [81] Quanquam totum opus Dei sit, non tamen _totaliter_ a Deo esse, quemadmodum totum pomum efficitur a sole, sed non a sole _totaliter_ et sine plantæ efficentiâ. (Pallavicini, Tom. i, p. 58.) Although the _whole_ work is of God, it is not _wholly_ of God--just as the _whole_ apple is produced by the sun, but not _wholly_ by the sun, and without the co-operation of the plant.