In his character, as he himself confessed, he was by nature a man of strong passions, but by long exercise in Stoical morality he had learnt to keep them under control. A young man, under the impression that Mendelssohn had done him a wrong, came one day to upbraid him, and indulged in one impertinence after another. Mendelssohn stood leaning on a chair, never turned his eye from his visitor, and listened to all his impertinences with the utmost Stoical patience. After the young man had vented all his passion, Mendelssohn went to him and said, "Go! You see that you fail to reach your object here; you can't make me angry." Still on such occasions Mendelssohn could not conceal his sorrow at the weakness of human nature. Not infrequently I was myself overheated in my disputes with him, and violated the respect due to such a man,--a fact on which I still reflect with remorse. Mendelssohn possessed deep knowledge of human nature,--a knowledge which consists not so much in seizing some unconnected features of a character, and representing them in theatrical fashion, as in discovering those essential features of a character, from which all the others may be explained, and in some measure predicted. He was able to describe accurately all the springs of action and the entire moral wheelwork of a man, and understood thoroughly the mechanism of the soul. This gave a character, not only to his intercourse and other dealings with men, but also to his literary labours. Mendelssohn understood the useful and agreeable art of throwing himself into another person's mode of thought. He could thus supply whatever was deficient, and fill up the gaps in the thoughts of another. Jews newly arrived from Poland, whose thoughts are for the most part confused, and whose language is an unintelligible jargon, Mendelssohn could understand perfectly. In his conversations with them he adopted their expressions and forms of speech, sought to bring down his mode of thinking to theirs, and thus to raise theirs to his own.