Gottfried and Bento...
I have never read much Leibniz. A philosopher at my university has a "Leibniz" vanity plate on his Toyota pickup truck, so I am reminded each day in the parking garage of the lacuna in my reading. I did audit Spinoza's Ethics with Ed Curley in grad school. Stewart refers to Spinoza by his nickname Bento.
But Stewart's book is an lively narrative of the history of ideas, full of wonderful biographical insights and cultural descriptions. I now realize how much I have dwelled in my study of philosophy in what a good friend calls our epistemology absorbed culture, that I knew so little about the circumstances of the work of these early moderns. The historical detail of Stewart's book is fascinating.
I don't know enough to evaluate thoroughly Stewart's major thesis regarding the meeting Leibniz had with Spinoza in Holland in late 1676, a few months before Spinoza died. Though Leibniz downplayed the importance of the meeting, Stewart states that "In fact, the meeting with Spinoza was the defining event of Leibniz's life. Everything before points toward it for resolution; and everything after points back for explanation" (p. 15). At least that is how far I have gotten in this book...
I do like this bio blurb on Stewart (b. 1963) from the inside back cover: "Matthew Stewart received his doctorate in philosophy from Oxford University. A founder of a management consulting firm, he retired in order to pursue a life of contemplation. He lives in New York."