Any one who has tact will see that, in a monograph, the apparatus of demonstration, while needing to be complete, ought to be reduced to what is strictly necessary. Sobriety is imperative; all parading of erudition which might have been spared without inconvenience is odious.[224] In history it often happens that the best executed monographs furnish no other result than the proof that knowledge is impossible. It is necessary to resist the desire which leads some to round off with subjective, ambitious, and vague conclusions monographs which will not bear them.[225] The proper conclusion of a good monograph is the balance-sheet of the results obtained by it and the points left doubtful. A monograph made on these principles may grow antiquated, but it will not fall to pieces, and its author will never need to blush for it. (2) Works of a general character are addressed either to students or to the general public. _A._ General works intended principally for students and specialists now appear in the form of "repertories," "manuals," and "scientific histories." In a repertory a number of verified facts belonging to a given class are collected and arranged in an order which makes it easy to refer to them. If the facts thus collected have precise dates, chronological order is adopted: thus the task has been undertaken of compiling "Annals" of German history, in which the summary entry of the events, arranged by dates, is accompanied by the texts from which the events are known, with accurate references to the sources and the works of critics; the collection of the _Jahrbücher der deutschen Geschichte_ has for its object the elucidation, as far as is possible, of the facts of German history, including all that is susceptible of scientific discussion and proof, but omitting all that belongs to the domain of appreciation and general views. When the facts are badly dated, or are simultaneous, alphabetical arrangement must be employed; thus we have Dictionaries: dictionaries of institutions, biographical dictionaries, historical encyclopædias, such as the _Realencyclopædie_ of Pauly-Wissowa. These alphabetical repertories are, in theory, just as the _Jahrbücher_, collections of proved facts; if, in practice, the references in them are less rigorous, if the apparatus of texts supporting the statements is less complete, the difference is without justification.[226] _Scientific manuals_ are also, properly speaking, repertories, since they are collections in which established facts are arranged in systematic order, and are exhibited objectively, with their proofs, and without any literary adornment. The authors of these "manuals," of which the most numerous and the most perfect specimens have been composed in our days in the German universities, have no object in view except to draw up minute inventories of the acquisitions made by knowledge, in order that workers may be enabled to assimilate