Russell’s first strictly philosophical work, this study remains one of the most important studies of Leibniz ever published. It established an approach to studying philosophers of the past that emphasises the philosophical rather than the historical. In Russell’s own words, ‘Philosophic truth and falsehood, in short rather than historical fact, are what primarily demand our attention in this inquiry.’ His interpretation emphasised the logical and deductive power of Leibniz’s system in opposition to the standard interpretations that had previously led Russell to believe that the Monadology was a kind of fantastic fairy tale.