Petzholdt passes some very severe judgments on some books that were once highly esteemed and on some that are unique surveys of a particular field. Whatever defects such books may have, they should not be damned hastily and completely. For example, Petzholdt's rejection (p. 160) of Johannes Tritheim's catalogue of Carmelite writers as "bibliographically completely worthless (Bibliographisch ganz ohne Werth)" is far too harsh. In 1576, after it had circulated in manuscript for almost a century, the Carmelites believed it deserved to be printed. Three more editions (1596, 1624, and 1643), all of which Petzholdt cites, came out during the next seventy years. Men obviously found it useful, and it is the basis of the modern Carmelite bibliography. The remark "Of altogether inferior bibliographical value (Bibliographisch von ganz untergeordnetem Werthe)" is even more unjust to Theodore Petreius's Carthusian bibliography (p. 161). However bad it may be, Petzholdt knew no other Carthusian bibliography. The only bibliography of a field may be incomplete, inaccurate, or badly arranged and it may even have all these defects, but it cannot be altogether worthless. Paul Lehmann, a competent authority in medieval bibliography and literary history, mentions Petreius and some other early writers of biobibliographies of religious orders and says that scarcely one of these writers has been superseded, although details in their work may need correction.[162] Petzholdt's critical remarks on bibliographies written in the second half of the eighteenth and the first half of the nineteenth century are very full and informative. Rarely does he err as badly as he does in a comment on Emil Weller's _Annalen_. This partial revision of G. W. Panzer, _Annalen der deutschen National-Literatur_ (1792-1805) is, like the original work, still valuable for German publications between 1500 and 1525. Weller's notes on books that he had seen contain no great number of serious mistakes. Nevertheless, Petzholdt says (p. 708): "A book that deserves very much to be noticed, although it by no means lacks bibliographical defects and [shows] hastiness and carelessness. It owes its great value to the wealth of the collections that the compiler was able to use." Weller was as difficult in his manners as Magliabecchi, Fontanini, and other bibliographers have been on occasion and had spoken unkindly of Petzholdt, but he did not deserve such a patronizing slur.