"Thus met Luther and Melancthon, and they were friends till death. We cannot sufficiently admire the goodness and wisdom of God in uniting two men so different, and yet so necessary to each other. What Luther had in warmth, elasticity, and force, Melancthon had in perspicuity, wisdom, and gentleness. Luther animated Melancthon; Melancthon moderated Luther. They were like the two forms of electric matter, the positive and the negative, which modify each other. Had Luther been without Melancthon, the stream had perhaps overflowed its bank; and, on the other hand, Melancthon, when without Luther, hesitated, and even yielded, where he ought to have stood firm.[520] Luther did much by vigour, and Melancthon perhaps did not less by pursuing a slower and calmer course. Both were upright, open, and generous, and both, smitten with the love of the word of eternal life, served it with a fidelity and devotedness which formed the distinguishing feature of their lives. [520] Calvin wrote to Sleidan: "Dominus cum fortiore spiritu instruat, ne gravem ex ejus timiditate jacturam sentiat posteritas." May the Lord supply him with a more resolute spirit, that posterity may not, through his timidity, sustain some grievous loss. The arrival of Melancthon produced a revolution, not only at Wittemberg, but throughout Germany and the learned world. His study of the Greek and Latin classics, and of philosophy, had given him an order, perspicuity, and precision of thought, which shed new light and inexpressible beauty on all the subjects which he discussed. The mild spirit of the gospel fertilized and enlivened his meditations, and the driest subjects when he expounded them were invested with a grace which fascinated all his hearers. The sterility which scholasticism had spread over education ceased, and a new mode of instruction and study commenced. "Thanks to Melancthon," says a distinguished German historian, "Wittemberg became the national school."[521] [521] Plank. It was, indeed, of great importance, that a man thoroughly versed in Greek should teach in this university, where the new developments of theology called masters and scholars to study the primitive documents of the Christian faith in the original languages. Thenceforth Luther set himself zealously to this task. Often did the meaning of a Greek term, which had previously been unknown to him, throw sudden light on his theological views. For example, how great his satisfaction and delight when he saw that the Greek word, μετανοια, which according to the Latin church, meant a penance, a satisfaction enacted by the Church, meant in Greek a transformation or conversion of heart. A thick mist all at once disappeared from before his eyes. The two meanings given to this word are sufficient to characterise the two churches.