At Berlin, Mendelssohn becomes an amanuensis to another poor rabbin, who could only still initiate him into the theology, the jurisprudence, and the scholastic philosophy of his people.  Thus, he was as yet no farther advanced in that philosophy of the mind in which he was one day to be the rival of Plato and Locke, nor in that knowledge of literature which was finally to place him among the first polished critics of Germany.

Some unexpected event occurs which gives the first great impulse to the mind of genius.  Mendelssohn received this from the companion of his misery and his studies, a man of congenial but maturer powers.  He was a Polish Jew, expelled from the communion of the orthodox, and the calumniated student was now a vagrant, with more sensibility than fortitude.  But this vagrant was a philosopher, a poet, a naturalist, and a mathematician.  Mendelssohn, at a distant day, never alluded to him without tears.  Thrown together into the same situation, they approached each other by the same sympathies, and communicating in the only language which Mendelssohn could speak, the Polander voluntarily undertook his literary education.

Then was seen one of the most extraordinary spectacles in the history of modern literature.  Two houseless Hebrew youths might be discovered, in the moonlit streets of Berlin, sitting in retired corners, or on the steps of some porch, the one instructing the other, with a Euclid in his hand; but what is more extraordinary, it was a Hebrew version, composed by the master for a pupil who knew no other language.  Who could then have imagined that the future Plato of Germany was sitting on those steps!

The Polander, whose deep melancholy had settled on his heart, died—­yet he had not lived in vain, since the electric spark that lighted up the soul of Mendelssohn had fallen from his own.

Mendelssohn was now left alone; his mind teeming with its chaos, and still master of no other language than that barren idiom which was incapable of expressing the ideas he was meditating on.  He had scarcely made a step into the philosophy of his age, and the genius of Mendelssohn had probably been lost to Germany, had not the singularity of his studies and the cast of his mind been detected by the sagacity of Dr. Kisch.  The aid of this physician was momentous; for he devoted several hours every day to the instruction of a poor youth, whose strong capacity he had the discernment to perceive, and the generous temper to aid.  Mendelssohn was soon enabled to read Locke in a Latin version; but with such extreme pain, that, compelled to search for every word, and to arrange their Latin order, and at the same time to combine metaphysical ideas, it was observed that he did not so much translate, as guess by the force of meditation.

This prodigious effort of his intellect retarded his progress, but invigorated his habit, as the racer, by running against the hill, at length courses with facility.