 Prus developed an original Utilitarian-inspired ethical system in his book, ""; his 1873 public lecture "", subsequently printed as a pamphlet, is a remarkably prescient contribution to what would, in the following century, become the field of logology ("the science of science").The movement's leader was Prus' friend, Julian Ochorowicz (1850–1917), a trained philosopher with a doctorate from the University of Leipzig.In 1872 he wrote