A compilation of papers delivered to a March 1982 conference on Hermeticism and the Renaissance held at the Institute for Renaissance and Eighteenth- Century Studies in the Folger Shakespeare Library in Washington, D.C., "Hermeticism and the Renaissance" embraces works on various sides of the debate sparked by the work of Frances Yates. She had basically asserted that Hermeticism could be detected in "virtually every aspect of sixteenth-century thought," a position bound to arouse strong feelings among historians who specialize in the period. The conferees hoped to evaluate charges that Yates had overemphasized the role of Hermeticism and that her conclusions had been accepted uncritically by too many scholars. It was clear from the papers delivered at the conference and reprinted in this volume that there is little difference of opinion as to Hermeticism's tremendous influence on Renaissance thought. Indeed, as is brought out in the book, even such mainstream writers as Paul Oskar Kristeller, Eugenio Garin and especially Andre-Jean Festugiere had already demonstrated that Hermeticism was an important feature of western thought during the period of transition from the Middle Ages to the early modern age. Critics remain, however, who feel that a conclusive case has yet to be made for Hermeticism's unique or seminal role in initiating Renaissance thought. One of the most interesting essays containing an element of careful criticism of Yates's position is "Hermes Trismegistus, Proclus, and the Question of a Philosophy of Magic in the Renaissance by Brian Copenhaver, a professor of history at Oakland University in Rochester, Michigan. Yes, says Copenhaver, Hermeticism was an influence, but it was only part and parcel of an overarching influence of Neoplatonism. Copenhaver examines major works of Renaissance writers, notably Marsilio Ficino and Cornelius Agrippa and finds that while Hermeticism is prominently in evidence in their books, the philosophical framework in which these Renaissance thinkers formulated their thoughts owed more to the late antique Platonic writers Proclus, Plotinus, Porphyry, and Iamblichus than it did to the Hermetic Corpus. The Hermetic Corpus was concerned with magic, alchemy, and the occult, but as a compilation of texts from various authors and diverse sources, it offered no coherent theoretical outlook in which to fit those magical and occult practices. Yet magic was not new in the Renaissance; it had definitely existed in the Medieval world. What distinguished Ficino, Pico della Mirandola, and later Agrippa, was not that they mentioned magic in their writings or expressed interest in it, but rather that they placed it in a new philosophical framework -- one which to a large extent served to "legitimize" the occult in a Europe where university learning was only beginning to emerge from the moldering cells of the monasteries. Copenhaver emphasizes that the Platonists of antiquity had had a great deal to say about magic even though modern students of philosophy tend to overlook these passages in their works. Interest in magic and the occult grew in the late Roman period. Plotinus, Iamblichus, and Proclus discussed theurgy and other aspects of magic -- all in the context of "natural" properties of the stars, certain minerals or other substances. In a short treatise appended to Copenhaver's article, Proclus treats the "priestly art" and says that priests make uses of natural forces in their magical activities. Mundane things, even plants and stones "follow the orbits" of heavenly luminaries. "Properties sown together in the sun are distributed among the angels, demons, souls, animals, plants, and stones that share them," says Proclus. Magic is simply an understanding of the cosmic "sympathies" of this or that earthly thing and the use of such understanding to "call forth" a god or perform other types of magic. Magic is the intelligent (and therefore effective) use of natural properties in things. This "scientific" understanding of magic, shared by all major Hellenistic Neoplatonists, was precisely what caught the attention of Ficino. "Why," he asked, "do we think that Love is a magician? Because the power of magic consists in love. An act of magic is the attraction of one thing by another in accordance with a certain natural kinship. The parts of this world, members of one living being, all originating from the same maker, are joined together in the communion of one another, assist each other to some extent, and suffer together when any one of them suffers. . . . Acts of magic, therefore, are acts of nature and art is her handmaid." (Copenhaver draws this quote from Ficino's Commentary on Plato's "Symposium") Copenhaver presents another passage from Ficino where he cites Plotinus as an authority for the notion that "everywhere nature is a magician." Nowhere do Hermetic texts so expressly present this unitary concept of the cosmos, although the Hermetic writers often clearly believed in such a cosmos. Copenhaver concludes from these passages and from the fact that Ficino actually cited Neoplatonists far more than he did the Hermetic Corpus. Similarly, Agrippa, whose interest in magic was even more that of a "practitioner" than was that of Ficino, derived his theoretical conceptualization (as well as many specific magical practices) of the place of magic in the cosmos (basically identical to that of Ficino) from Neoplatonism. Thus, far from repudiating or denying the role of magic in the Renaissance, Copenhaver reemphasizes it. Contrary to Yates, however, he brings out the fact that Neoplatonism (of which Hermeticism was one offshoot) was the Weltanschauung of which Renaissance magic was a part. Furthermore, it was to Neoplatonism that the great thinkers of the Renaissance turned for the theoretical framework they needed to make magic acceptable. Magic was not, as Augustine and other medieval churchmen had thought, cavorting with demons, but simply making use of the natural properties in the world around us. Not only is this article important insofar as it clarifies a fine point of history, giving the Neoplatonists their due. It is also valuable in that it places Renaissance magic in a fully articulated framework which was, in a sense, scientific, in that it clearly would stimulate an investigation into the natural properties in things and into the interconnections present in the cosmos. If magic is the sum total of natural processes, then we can practice magic only by understanding nature and manipulating it. Since the practice of magic never died out in the Middle Ages, Copenhaver's theory makes clear how Ficino and the Renaissance writers effected a change in thinking -- not by some supposed introduction of Hermetic magic, but by a formulation of the role of magic as a part of nature that would compel people to transcend the confines of scholasticism. The new paradigm of the cosmos, one might say, was born here. Another essay of great interest was that of Paola Zambelli, a professor of the history of philosophy in Florence, who wrote of "Scholastic and Humanist Views of Hermeticism and Witchcraft." Hermeticism and witchcraft both existed throughout the Middle Ages, she notes, but in the last half of the fifteenth century they underwent a "decisive renewal and a kind of codification" both in Italy and in Germany. Zambelli singles out Ficino's world outlook as reflected in his works "De Amore" and "De Vita Coelitus," and notes how different it was from that of earlier writers on magic. Guillaume d'Auvergne, to be sure wrote about "magia naturalis" too, but his concept of human nature was Augustinian, i.e., human nature was corrupted by "original sin" and therefore natural processes were sinful. Ficino, Pico della Mirandola, Agrippa and many other subsequent humanist thinkers stressed the oneness of nature, the continuum represented in the order of the cosmos. For them, nature was not the way to hell, but the route to heaven. Zambelli emphasizes that magic (which Copenhaver showed was understood as simply natural activity) in the works of Pico actually became "the dynamic center of his world view." This is a clear revolution in approach from what had been the case before, and what was important was not the introduction of magic (it had been around for a long time) but the "codification" which magic underwent at the hands of Ficino, Pico and later humanist writers. The famous German humanist, Johannes Reuchlin, produced a book -- De Verbo Mirifico -- which was "saturated with Ficino's Hermeticism, natural magic, and Pico's cabala." Reuchlin, in turn, became the "most important link" between Pico and Cornelius Agrippa, one of the best known Renaissance occult practitioners. Although Zambelli's focus is somewhat different from that of Copenhaver, her article reinforces many aspects of Copenhaver's position, in particular in its emphasis on the role played by the Renaissance humanists as "codifiers" of the occult, their recasting it in the framework of a holistic world outlook. Other articles in the collection are of considerable interest as well. Leland L. Estes presented evidence for Giordano Bruno's being influenced by Lullism while in France. Isaac Newton's interest in alchemy is the subject of B. J. T. Dobbs's article about the English scientist's Commentary on the "Emerald Tablet." As was the case with the Renaissance writers on magic, Newton saw alchemical processes as organic. Although he believed that matter was itself passive and required spirit to activate it and drive it to effect chemical reactions and alchemical transformations, in accordance with classical philosophy he felt that "all matter duly formed is attended with signes of life." Much of Newton's effort, therefore, went towards discovering the spiritual agent which, as it were, animated matter. In his commentary on the Emerald Tablet, Newton explained that Hermes Trismegistus symbolized that "activating spirit." Newton's commentary fully reflects his "curiosity about matter, its changes, and its organization." Thus there can be demonstrated a "basic unity to Newton's work," writes Dobbs, and the author of the Principia Mathematica did not somehow "deviate" into alchemy. Rather his alchemical interests were fully consistent with his general concern for natural philosophy. Other articles explore the evolution of Hermetic tendencies in subsequent centuries, often in non-scientific directions as in the rise of Rosicrucianism and Freemasonry. Allen Debus's article, on the other hand, explores the contribution of chemical philosophers in Eighteenth-Century France. He demonstrates that although the mechanistic approach to chemistry had made great inroads, alchemy remained of considerable interest to chemists, as evidenced by publications such as the "Journal des Scavans" and numerous books. Elsewhere in the volume the role of Hermeticism in the architecture and art is examined, and questions are raised about the extent to which the debates over the "hidden meanings" of Egyptian hieroglyphs reflected Hermetic preoccupations. For the student of the scientific revolution Hermeticism and the Renaissance is a valuable source. The contributions of Copenhaver and Zambelli in particular help track the emergence of a paradigm that, though it drew on ancient sources and ideas, constituted the theoretical basis for an entirely new approach to the nature and the universe.