Luther's glance was too penetrating not to discover the contradictions into which his opponent had fallen. And accordingly, in his reply he endeavours to fasten the philosopher in the net in which he had entangled himself. "If the passages you quote," said he, "establish that it is easy for us to do good, why do we dispute? What need have we of Christ and of the Holy Ghost? Christ would then have acted foolishly in shedding his blood to acquire for us a power that we already possessed by nature." In truth, the passages cited by Erasmus must be taken in quite a different sense. This much debated question is clearer than it appears to be at first sight. When the Bible says to man, Choose, it presupposes the assistance of God's grace, by which alone he can do what it commands. God, in giving the commandment, also gives the strength to fulfil it. If Christ said to Lazarus, Come forth, it was not that Lazarus had power to restore himself; but that Christ, by commanding him to leave the sepulchre, gave him also the strength to do so, and accompanied His words with His creative power. He spoke, and it was done. Moreover, it is very true that the man to whom God speaks must will; it is he who wills, and not another; he can receive this will but from God alone; but it is in him that this will must be, and the very commandment that God addresses to him, and which, according to Erasmus, establishes the ability of man, is so reconcilable with the workings of God, that it is precisely by these means that the working is effected. It is by saying to the man "Be converted," that God converts him. [Sidenote: LUTHER'S SECOND AND THIRD PARTS.] But the idea on which Luther principally dwelt in his reply is, that the passages quoted by Erasmus are intended to teach men their duty, and their inability to perform it, but in no way to make known to them the pretended power ascribed to them. "How frequently it happens," says Luther, "a father calls his feeble child to him, and says: 'Will you come, my son! come then, come!' in order that the child may learn to call for his assistance, and allow himself to be carried."[584] [584] L. Opp. xix. 55.