“Of a truth this man would have surpassed us all if he had had the master-pieces of art constantly before him.” —Raphael.

“Hardly any master has scattered with so lavish a hand all that the soul has conceived of fervid feeling or pathos, all that thought has grasped of what is strong or sublime, all that the imagination has conceived of poetic wealth; in no one has the depth and power of the German genius been so gloriously revealed as in him.” —Lubke.

“He was content to be a precious corner-stone in the edifice of German Art, the future grandeur of which he could only foresee.” —Richard Ford Heath.