necessary root of the rare flower; and he had, too, the sympathetic, unselfish feeling which we are wont to summarise shortly as a good heart, and which is the first essential to good manners. When Lessing came to Berlin, about 1745, his play of _Die Juden_ was already published, and his reputation sufficiently established to make him an honoured guest at these little literary gatherings. Something of affinity in the wide, unconventional, independent natures of the two men; something, it may be, of likeness in unlikeness in their early struggles with fate, speedily attracted Lessing and Mendelssohn to each other. The casual acquaintance soon ripened into an intimate and lifelong friendship, which gave to Mendelssohn, the Jew, wider knowledge and illimitable hopes of the outer, inhospitable world--which gave to Lessing, the Christian, new belief in long-denied virtues; and which, best of all, gave to humanity those ‘divine lessons of Nathan der Weise,’ as Goethe calls them--for which character Mendelssohn sat, all unconsciously, as model, and scarcely idealised model, to his friend. It was, most certainly, a rarely happy friendship for both, and for the world. Lessing was the godfather of Mendelssohn’s first book. The subject was suggested in the course of conversation between them, and a few days after Mendelssohn brought his manuscript to Lessing. He saw no more of it till his friend handed him the proofs and a small sum for the copyright; and it was in this way that the _Philosophische Gespräche_ was anonymously published in 1754. Later, the friends brought out together a little book, entitled _Pope as a Metaphysician_, and this was followed up with some philosophical essays (‘Briefe über die Empfindungen’) which quickly ran through three editions, and Mendelssohn became known as an author. A year or two later, he gained the prize which the Royal Academy of Berlin offered for the best essay on the problem ‘Are metaphysics susceptible of mathematical demonstration?’ for which prize Kant was one of the competitors.