Contributions from
the Museum of History and Technology:
Paper 8
The Natural Philosophy of
William Gilbert and His Predecessors
W. James King
By W. James King
THE NATURAL PHILOSOPHY OF
WILLIAM GILBERT
AND HIS PREDECESSORS
Until several decades ago, the physical sciences wereconsidered to have had their origins in the 17th century—mechanicsbeginning with men like Galileo Galilei andmagnetism with men like the Elizabethan physician andscientist William Gilbert.
Historians of science, however, have traced many of the17th century's concepts of mechanics back into the MiddleAges. Here, Gilbert's explanation of the loadstone andits powers is compared with explanations to be found inthe Middle Ages and earlier.
From this comparison it appears that Gilbert can bestbe understood by considering him not so much a heraldof the new science as a modifier of the old.
The Author: W. James King is curator of electricity,Museum of History and Technology, in the SmithsonianInstitution's United States National Museum.
The year 1600 saw the publication by an Englishphysician, William Gilbert, of a book on theloadstone. Entitled De magnete,[1] it has traditionallybeen credited with laying a foundation for themodern science of electricity and magnetism. Thefollowing essay is an attempt to examine the basisfor such a tradition by determining what Gilbert'soriginal contributions to these sciences were, andto make explicit the sense in which he may be consideredas being dependent upon earlier work. Inthis manner a more accurate estimate of his positionin the history of science may be made.
Figure 1.—William Gilbert's Book on the Loadstone, Title Page of the First Edition,from a Copy in the Library of Congress. (Photo courtesy of the Library of Congress.)One criterion as to the book's significance in thehistory of science can be applied almost immediately.A number of historians have pointed to the introductionof numbers and geometry as marking awatershed between the modern and the medievalunderstanding of nature. Thus A. Koyré considersthe Archimedeanization of space as one of the necessaryfeatures of the development of modern astronomyand physics.[2]A. N. Whitehead and E. Cassirer have turned to measurementand the quantification of force as marking thistransition.[3]However, the[Pg 124]obvious absence[4]of such techniques in De magnete makes it difficult to considerGilbert as