Russell's book on Leibniz appeared in 1900. That it is important, because of its subject and because of its author, hardly needs to be argued. An examination of it, or of parts of it, after more than half a century is therefore in order. Yet the title I chose indicates only part of my intent. The other part is to examine certain ideas, irrespective of what either Leibniz or Russell thought and of what the latter thought about the thoughts of the former. The title best suited to this part is Individuals, Natures, Relations, and Change. The mixed form of presentation, analytic and quasihistorical, has very great advantages. For the nature of the philosophical enterprise is such that an analyst is lost without some grasp or, at least, some image of “structural history.” The danger is that only very few, if any, are masters of two trades; in this case, logical analysis and historical scholarship. I, for one, make no pretense whatsoever of being a scholar. Naturally, I have read in Leibniz; and I did not skip or take lightly anything in the letters to Arnauld and Clarke; but I have by far not read everything that is available. Reading about Leibniz, aside from Russell, of which I did but little, I found Latta and, particularly, Joseph sometimes helpful. More often, though, I felt that the former's Hegelianism and the latter's Aristotelianism had got between them and their subject.