The strained relation between these two men never came from external things, such as human rank and fame, much less from other advantages, but always from matters of church and doctrine, and chiefly from the fundamental difference of their individualities; they repelled and attracted each other "because nature had not formed out of them one man." It cannot be denied, however, that Luther was the more magnanimous, for however much he was at times dissatisfied with Melanchthon's actions, he never uttered a word against his private character; however Melanchthon sometimes evinced a lack of confidence in Luther. In a letter to Carlowitz, before the Diet of Augsburg, he protested that Luther on account of his hot-headed nature exercised a personally humiliating pressure upon him.