These words alone suffice to show us on which side strength was to be found. To accomplish a religious transformation, there is need of a firm and living faith. A salutary revolution in the Church will never proceed from philosophical views and mere human opinions. To fertilize the earth after a long drought, the lightning must cleave the cloud and the windows of heaven must be opened. Criticism, philosophy, and even history may prepare the way for the true faith, but cannot supply its place. In vain would you clear the water-courses and repair the dikes, so long as the rain does not come down from heaven. All human learning without faith is but an aqueduct without water. [Sidenote: WITTICISM OF ERASMUS.] Whatever might have been the essential difference between Luther and Erasmus, the friends of Luther, and even the reformer himself, had long hoped to see Erasmus unite with them against Rome. Many sayings which his caustic humour let fall were quoted, as showing his disagreement with the most zealous defenders of Romanism. One day, for instance, when he was in England, he had a keen discussion with Thomas More on transubstantiation: "Believe that you have the body of Christ," said the latter, "and you have it really." Erasmus made no reply. Shortly after, when leaving England, More lent him a horse to carry him to the seaside; but Erasmus took it with him to the Continent. As soon as More was informed of this, he wrote very severely to him about it. Erasmus, by way of reply, sent him these lines:-- "You said of the bodily presence of Christ: Believe that you have, and you have him! Of the nag that I took my reply is the same: Believe that you have, and you have him!"[564] [564] Quod mihi dixisti nuper de corpore Christi: Crede quod habes, et habes; Hoc tibi rescribo tantum de tuo caballo: Crede quod habes, et habes. Paravicini Singularia, p. 71. It was not only in England and Germany that Erasmus had thus become known. It was said at Paris that Luther had only opened the door, after Erasmus had picked the lock.[565] [565] Histoire Cathol. de notre temps, par S. Fontaine, de l'ordre de St. François, Paris, 1562. The position taken by Erasmus was by no means easy: "I shall not be unfaithful to the cause of Christ," wrote he to Zwingle, "at least so far as the age will permit me."[566] In proportion as he beheld Rome rising up against the friends of the Reformation, he prudently retreated. He was applied to from all quarters; the pope, the emperor, kings, princes, scholars, and even his most intimate friends, entreated him to write against the reformer.[567] "No work," wrote the pope, "can be more acceptable to God, and worthier of yourself and of your genius."[568] [566] Quantum hoc seculum patitur. Zw. Epp. p. 221. [567] pontifice, a Cæsare, a regibus, et principibus, a doctissimis etiam et carissimis amicis huc provocor. Erasm. Zw. Epp. p. 308.