We must look with a critical eye at Peignot's classification. Since he has an article on the bibliography of bibliographies, he should not put Labbé, _Bibliotheca bibliothecarum_, in "Des livres en général" (p. 387). Boulard's treatise on bibliographical method stands on the border of what is admissible and should certainly not be placed with "Des livres rares," a list of catalogues of rare books (p. 396). Georg Draud, _Bibliotheca classica_, a classified compilation of titles listed in the semi-annual catalogues of the German booktrade, includes juridical works as a matter of course, but it is not correctly placed in "Droit" (p. 254). Anton Francesco Doni's _La libraria_ is a catalogue of Italian books and is not, as Peignot lists it (p. 95), a catalogue of a private library. Peignot has seen many of the books that he cites and in this regard surpasses his predecessors. He does not, however, report German authors' names and titles (even titles written in Latin) with satisfactory accuracy.[130] I am not disposed to judge him very harshly for this fault because the language was no doubt strange to him and the books were probably not available. A more serious fault is, it seems to me, his neglect of obviously important books that he either could have seen or should have known. I cannot understand how he overlooked such authorities on church history and theology as Louis Ellies Du Pin, Jacques LeLong, and J. G. Walch. He knows only two of the six eighteenth-century bibliographies of diplomatics that Namur commends (pp. xvii-xix), but all of them are, it must be acknowledged, German works and therefore probably not within his reach. These comments on Peignot's faults can easily obscure our estimate of his merits. His succinct and abundant comments were no doubt useful when he wrote and are still valuable. His chronological arrangement of titles is a spur to historical meditations on the development of many fields of study. A modern scholar finds it hard to duplicate some information that Peignot has assembled. Where else can he easily find bibliographies of the collections of Latin poets,[131] dictionaries,[132] encyclopedias,[133] translators of the classics,[134] and accounts of royal and noble writers?[135] His review of bibliographies of incunabula lays a foundation for a history of such works,[136] and so also does his survey of bibliographies of medicine.[137] The most amusing list in Peignot's _Répertoire_ is a collection of bibliographies of men who practised trades or were members of professions having little connection with literature.[138]