[“Omnia in Eo:” compendium of Jewish Law]. (Attributed to Aaron HaKohen of Lunel).

Considerable scholarly and bibliographic research has been devoted to the identification and dating of this work - as early as de Rossi’s catalogue entry in his Annales Hebraeo-Typographici of 1799. Steinschneider definitively attributed the Kol Bo to Naples, circa 1490. Though his description was followed by many a bibliographer, Moses Marx was a dissenting voice: “There is not the slightest reason for ascribing the book to the city of Naples.” A.K. Offenberg noted the peculiarity of the typeface: “The same type is not used in any other known Hebrew incunable” (Offenberg, p. 92). But if typographical analysis is to no avail, neither does examination of the watermarks produce much conclusive evidence. Offenberg concludes: “The book was printed somewhere in Italy about 1490… Naturally, it can indeed have been printed in Naples itself, particularly since the greatest part of Hebrew incunabula were published there about 1490, but it is not possible to be certain of this on the evidence of the paper alone” (p. 96). See M. Steinschneider, Catalogus Librorum Hebraeorum (1852-60) Addenda et Corrigenda, col. LXXXIII; M. Marx, Studies in Bibliography and Booklore 1:1 (1953) p. 37, no. 38; A.K. Offenberg, The Dating of the Kol Bo; Watermarks and Hebrew Bibliography in: Studia Rosenthaliana 6:1 (1972) pp. 86-106. Scholars are still debating the identity of the author and the relation of the book to R. Aaron Hakohen of Lunel’s Orchoth Chaim, whose contents overlap the material in the Kol Bo. There are those who maintain that the Kol Bo is by the same author, just an earlier draft of the Orchoth Chaim.