 Moreover, Bolzano was also learned in the history of philosophy; he had great historical knowledge which he injected into his various works. Thus in the second edition of Athanasia, for instance, there is added an extensive appendix with a “critical survey of the literature concerning immortality since 1827”, and Bolzano’s essay on the concept of beauty contains a detailed list of definitions of the concept of the beautiful, which were proposed by a variety of philosophers (1843b, 45–92); likewise the Theory of Science contains in the notes a wealth of historical material, which makes it a great source for the historian of logic.