The paper takes a retrospective look at the work of Henry Evelyn Bliss, classificationist theorist and author of the "Bibliographic Classification". Major features of his writings and philosophy are examined and evaluated for the originality of their contribution to the corpus of knowledge in the discipline. Reactions to Bliss's work are analysed, as is his influence on classification theory of the 20th century. Contemporary work on knowledge organization is seen to continue a number of strands from Bliss's original writings. His standing as a classificationist is compared with that of Ranganathan, with the conclusion that he is not given the credit he deserves. (Contains 2 tables.)