The name Rasmus Nielsen (1809-84) is not well known to Kierkegaard scholars, even though he was an important figure in his own right; indeed, Nielsen was one of Denmark’s greatest philosophers during a period that witnessed a blooming of Danish philosophy. Moreover, Nielsen played a role in most every phase of Kierkegaard’s life. Kierkegaard owned several of Nielsen’s works, and his journals are full of references to him. There also survives a fairly extensive correspondence of letters that passed between them.