Gould, Theory of the Living Earth

58   This View of Life Natural History 5/97  

Codex Leicester, and occupies several full pages of text--one, for example, entitled "Of the Flood and of marine shells," and another, "Refutation of such as say that the shells were carried a distance of many days' journey from the sea by reason of the Deluge."

Second, Leonardo dismisses, even more contemptuously, various Neoplatonic versions of the theory that fossils are not remains of ancient organisms at all, but rather manifestations of some plastic force within rocks, or some emanation from the stars, capable of precisely mimicking a living creature in order to illustrate the symbolic harmony among realms of nature: animal, vegetable, and mineral. If fossils really belong to the mineral kingdom, then their position on the tops of mountains ceases to be anomalous, as we need no longer believe that these objects ever inhabited the seas.

Leonardo made observations 7 to 9 to refute this Neoplatonic theory that fossils "grew" within their entombing rocks and do not represent the remains of organisms. If marine fossils are inorganic, why don't they "grow" in all strata, rather than only in rocks carrying abundant evidence of an oceanic origin (observation 7). If fossils belong to the mineral kingdom, why should they so often grow in fragments and jumbles looking exactly like piles of shells on our beaches, or layers deposited by rivers in lakes and ponds (observation 8). Most convincingly, if fossils grow from inorganic "seeds" in the rocks, how can they expand, year by year, as indicated by growth bands in their shells, without fracturing the surrounding matrix (observation 9).

Leonardo reserved his choicest invective for what he regarded as the lingering magical content of this Neoplatonic theory of signs and signatures (although the issue remained alive--and quite lively--within Western science until the late seventeenth century. The Mundus subterraneus (1664) of the great Jesuit scholar Athanasius Kircher represents the last seriously cogent defense of the Neoplatonic position). Leonardo writes:

And if you should say that these shells have been and still constantly are being created in such places as these by the nature of the locality and through the potency of the heavens in those spots, such an opinion cannot exist in brains possessed of any extensive powers of reasoning because the years of their growth are numbered upon the outer coverings of their shells [observation 9 again]; and both small and large ones may be seen, and these would not have grown without feeding or feed without movement, and here [that is, in solid rock] they would not be able to move.

. . .Ignoramuses maintain that nature or the heavens have created [fossils] in these places through celestial influences.

B ut demonstrating that Leonardo made his paleontological observations to refute the prevailing theories of his time scarcely establishes my argument that he must be evaluated as a thinker immersed in his own premodern context and not judged for his remarkable foreshadowing of twentieth-century views--for a true spaceman would also have to refute the fallacies of his surroundings in order to introduce superior views from his time warp (just as Hank Morgan had to reject the running messenger service in favor of a telephone call for summoning Sir Lancelot's bicycle corps). I must advance a further claim--one that can be particularly well documented in Leonardo's case.

Just as Leonardo made his astute observations to refute prevailing theories of fossils, he also urged his interpretations in support of his own favored theory of the earth. ("All observation must be for or against some view"). And the positive prod for Leonardo's paleontological observations could not have been more squarely Renaissance or late medieval, more firmly attached to his own time and concerns--and not to ours. Leonardo observed fossils as part of his quest to support a distinctive theory of the earth--a framework that would be seriously weakened if either Noah's flood or the Neoplatonic theory of fossils were true. If Leonardo had not been so devoted to his "antiquated" theory of the earth. I doubt that he would ever have been inspired to make his wonderfully "modernist" observations about fossils--for the notebooks invariably present his observations as arguments to support his theory.

Leonardo loomed so much larger than life, even in the eyes of his contemporaries, that a potent mythology began to envelop him right from the start. Only thirty years after Leonardo's death, Giorgio Vasari published a first biography full of such touching tall tales as Leonardo's death in the arms of King Francis I. (Francis did admire Leonardo greatly, but he and his entire court had decamped to another town on the day of Leonardo's demise. (A. Richard Turner has written an entire, and fascinating, book on the history of the Leonardo legend through the ages--Inventing Leonardo, University of California Press, 1994.) One prominent component of the myth--that Leonardo was an unlettered man who could only work by observation and therefore gained great (if ironic) benefit from not knowing the false traditions of medieval Scholasticism--must be refuted if my case for his medieval impetus has merit. For how could I assert such a controlling context if Leonardo never knew or studied the prevailing traditions of printed scholarship in his time?

As the illegitimate son of a Florentine notary, Leonardo grew up in reasonably comfortable but nonscholarly circles and received only a limited formal education. Most importantly, he did not learn Latin, then the nearly universal language of intellectual communication. But Leonardo did study Latin assiduously in later life, even if he never attained more than a halting knowledge. (I love Martin Kemp's statement in his superb book Leonardo da Vinci: The Marvelous Works of Nature and Man: "It is rather humbling to think of Leonardo in his late thirties secretly

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