This is the landmark book of the field Lovejoy single-handedly invented (and of which perhaps he is still the sole master): the history of ideas. He wrote some other essays about different ideas and their histories (one of my favorites is about the concept of the "fortunate fall"), but this is his magnum opus and it reads like a thrilling detective story. He's a sleuth looking underneath the various intellectual currents over a 1500 year period in western thought, finding a culprit lurking in many of the failed philosophies and fashions we think we know -- the idea of the "great chain of being" foisted on us by Plato and his heirs.

The book is worth the first two exhilarating chapters alone. After that, the book can get pretty heavy at times; and Lovejoy's long-thought-train, multi-disciplinary, multi-lingual approach can leave one a little lost in some passages. Keep going to the end, though -- the book gradually builds up to an amazing set of climaxes in the last few chapters. He shows how the various thinkers draw out all of the contradictory implications of the the original idea until the thing peters out into a strewn splatter of waste.

It's funny and thought-provoking, and it will peel your mind like an onion.

Lovejoy was a professor of philosophy at Johns Hopkins University. This book represents an expanded version of a series of lectures given by Lovejoy at Harvard during the second half of the academic year 1932-33. The fact that this book remains in print over 60 years later is testimony to the fact that it has become a classic.

The book concerns the Great Chain of Being, a way of looking at reality that can be traced to Plato and Aristotle. We begin with the supposition that existence is superior to non-existence. A good God, Plato argues, would allow any non-contradictory being to exist. God thus created a Universe full of all possible things. This Lovejoy calls the principle of plenitude, the maximally full World. From Aristotle later writers evolved the idea that changes in Nature were continuous; that "Nature makes no leaps." This became the principle of continuity. Eventually, philsophers would postulate a vast chain of Beings stretching from the perfect (God) to the nearly non-existent (lifeless matter). Mankind was somewhere in the middle of the chain - above the animals (specifically the Ape), but below the Angels.

The principles of continuity and plenitude were integral to the thinking of many philosophers and scientists. Lovejoy traces how numerous thinkers - St. Thomas, Liebniz, and Schelling figure most prominently - wrestled with the implications of plenitude and continuity. Could plenitude explain evil? How could one account for change if God had created the chain at the beginning of History? Lovejoy also traces the fate of two contradictory Platonic conceptions of God. Plato had painted God as an Other-Worldly and self-sufficient being on one hand while also describing how God had manifested his thought in the real world. The chain was God's thought concretely expressed.

This is not a book for someone who is a neophyte to philosophy. However it is an important book, particularly for understanding the intellectual foundations of much scientific and philosophical speculation of the past several hundred years. Lovejoy succeeds in showing how the Great Chain of Being lead to a number of surprising intellectual developments including Romanticism's appreciation for diversity. His writing is very clear. At times the book is amusing and it is always pleasurable to read.