A major portion of Reeves's book is devoted to the impact of Galileo's discovery of what was called "secondary light" or "ashen light" (i.e., the reflection of sunlight from the earth back to the moon); today it is usually called "earthshine." Coupled with this was the question of the substance of the moon. Also attention is given to the new star of 1604 and the aurora borealis. In all, Reeves studies seven paintings by four artists. Four of the paintings are by Galileo's friend Lodovico Cigoli; the others are by Peter Paul Rubens, Diego Velazquez, and Francisco Pacheco.

Over 40 years ago the art historian Erwin Panofsky alerted both art and science historians to the scientific implications of Cigoli's painting of the Virgin on the dome of the Pauline Chapel in Santa Maria Maggiore (Rome). Cigoli worked on this painting from 1610-12. It was during the winter of 1609-10 that Galileo made his celebrated telescopic discoveries, which he published in the spring in his Sidereus Nuncius; about 6 months later Cigoli began his painting. As Panofsky pointed-out, the moon at the feet of the Virgin (the moon being an attribute of her) was not depicted in the conventional style--namely, as non-opaque, smooth, and near perfect - which had its origin in the ancient concept of a perfect celestial world; rather, Cigoli painted the moon as Galileo had described it--as "uneven, rough, and full of cavities and prominences."

More recently, in his book The Heritage of Giotto's Geometry (1991) and several articles, Samuel Y. Edgerton, Jr. has developed further the interrelationship between art and science in the Renaissance, particularly showing how Renaissance artistic techniques and skills influenced Galileo's work in science. It is important to realize that Galileo was a skilled artist who late in life once said that he wished he had made art his career. Indeed he taught Cigoli perspective at the Accademia del Disegno in Florence; Galileo, in turn, later considered Cigoli the best painter alive. Galileo's deft draughtsmanship is clearly and beautifully revealed in an extant series of wash drawings of the moon, reproduced in many places (e.g., Edgerton's book) but unfortunately not in Reeves' book. In fact, Reeves almost downplays Galileo's artistic ability by going at lengths to find sources (e.g., Leonardo da Vinci) for his skill in depicting light and shadow. (This point is also made by Edgerton in his review of Reeves's book, elsewhere.)

But her detailed scholarship certainly comes to fruition in the analyses of the paintings of Cigoli: Reeves has written a masterful study of the impact of Galileo's science on Cigoli's art. She confirms the connection of the painting of the Virgin to Galileo's discoveries and shows how Cigoli responded to the controversy over the substance of the moon, a dispute that was theological at the core. Although the concept of the Immaculate Conception of Mary was not made dogma in the Catholic Church until 1854, the idea was planted much earlier and was believed by many in Galileo's time - primarily, it seems, by those opposed to his assertions about the substance of the moon. Since the moon was a symbol of the Virgin, it too must be and remain "pure." Hence Galileo's discovery contradicted not only an ancient Aristotelian (scientific) belief about the moon; it also came up against a present (theological) belief about the nature of Mary.

Now it comes as no surprise to this historian of science and art to see again that in the 17th century theological matters were intertwined with scientific ones. But even accustomed as I am to this, I was still surprised to see the extent to which some theologians would go to preserve their belief system in reaction to Galileo's assertion. Thus, e.g., they played a word game (which goes back at least to the 14th century) relating "mare" to "Mary": mare (plural, maria) is Latin for the dark areas of the moon, and Maria is Spanish for Mary. Of course, this was not wordplay for them but serious symbolism. Yet it was symbolism at variance with the contemporary intellectual context of naturalism in art, whereby a distinction was made between symbolism and reality.

One fascinating and rather amusing twist to this controversy involves the interaction of art and science. Although Galileo's skill as an artist aided him in portraying the opaque and rough moon, some critics turned this around by asserting that the seemingly 3D mountains and valleys on the moon "seen" by Galileo were merely illusions on a smooth surface--like the 3D illusions on a flat Renaissance painting!

Reeves's fascinating study is confined to the early 17th century. For a longer view, I look forward to the publication of Scott Montgomery's forthcoming, Expanding the Earth: The Moon and Western Imagination, a book on the history of the conception and depiction of the moon since ancient times. I have read the manuscript and can assert that it will be as important to the "big picture," as Reeves's splendid book is for the important era she has explored in such detail.