The following letters of Humboldt furnish a contribution of the highest importance to the true, correct, and unveiled representation of his genius and character. That they should be delivered to publicity after his death was his desire and intent, which have found their positive impression in the words preceding this book as its motto. Never has he spoken out his mind more freely and sincerely, than in his communications with Varnhagen, his old and faithful friend, whom he esteemed and loved before all others. In him he placed an unlimited confidence; with him he deposited those letters received by him, which he desired to be saved for their importance, while he used to destroy nearly all others. He presumed that Varnhagen, the junior of the two, would survive him. Varnhagen, however, died first and transmitted the duty—a doubly sacred one—to me, of publishing this memorable evidence of the life, the activity, and the genius of this great man. In the accomplishment of this charge it was a religious duty to leave every word unchanged as written down. I would have thought it an offence to Humboldt’s memory had I had the arrogance to make the slightest alterations of his words. For the same reason I did not think myself authorized to grant the request—however well-meaning it may have been—of the publisher, that I should make such alterations, nor could I accord the least influence to my own feelings or to personal regards. There was but one consideration to be obeyed—the _eternal truth_, for an adherence to which I am responsible to Humboldt’s memory, to History and Literature, and to the will of him who enjoined this duty upon me. And therefore the legacy, intrusted to my hands, will appear full and complete, as it was received. The interest of Humboldt’s letters is sometimes pleasantly heightened by entries in Varnhagen’s diary—they will indicate the verbal sentiments of Humboldt in addition to those written by him. Of Varnhagen’s letters few only were preserved or could be found. In the little, however, which is known, the noble friendship, the constant, never-ceasing mental activity, the faithful fellowship in their mutual efforts in behalf of science and liberty, in all of which Humboldt and Varnhagen were so many years united, find a sufficient expression. The letters of many other distinguished and celebrated persons, which are also added, will show Humboldt in his world-wide connexions, in his manifold relations to savans and authors, to statesmen and princes, all of whom approached him with reverence. LUDMILLA ASSING. BERLIN, February, 1860. HUMBOLDT’S LETTERS. 1. HUMBOLDT TO VARNHAGEN. BERLIN, _September 25th, 1827_. MY HONORED FRIEND: Allow me to present you with the best copy of my essay[1] left me.