Since at this moment, when your letter arrives, I am plagued with a visit, I shall write just these few lines. Kertbeny s  address: No I/III (what the III means I do not know; perhaps, third floor) Behrenstrasse. Now permit me a word. Since you and Engels were of the opinion that it would be useful, I gave way to having this advertisement in the Gartenlaube. I was decisively opposed to it. And now I ask you urgently, to give up this joke definitely. It leads to nothing except that fellows like Keil and Daheim believe that one belongs to the pack of great literary and other men, and needs or desires their protection. I think it is more harmful than useful and beneath the dignity of a scientific man. For example, Meyer s Konversationslexikon wrote asking me for a biography a long time ago. Not only did I not send one, but I did not even answer their letter. Everybody must reach salvation in his own way. As for Kertbeny, he is a confused, boastful, importunate literary idler and the less one has to do with him, the better.
Marx-Engels Correspondence 1866