Abstract

At a time when they had largely fallen into disrepute Bolzano reactivated the distinctions between ‚clear‘ and ‚obscure‘, ‚distinct‘ and ‚confused‘ ideas. In the central sections of this paper I offer a critical reconstruction of the explanations of these pairs of opposita which are to be found in vol. III of Bolzano's monumental Wissenschaftslehre . I then provide a detailed account of its Leibnizian counterparts that were well-known to the ‚Bohemian Leibniz‘, and finally I evaluate Bolzano's criticism thereof