Boyle, Robert (1627–1691)

views updated

BOYLE, ROBERT
(1627–1691)

Robert Boyle, the English natural philosopher, was the fourteenth child of Richard Boyle, the first earl of Cork, who by judicious marriages and land purchases had made himself the most influential man in Ireland and the richest in England. The political and financial fortunes of the earl of Cork fluctuated considerably during his son's lifetime, but ultimately Robert Boyle inherited a considerable income, which greatly facilitated his scientific researches.

In October 1635, Boyle entered Eton, which with Sir Henry Wotton as provost was a notable center of culture and learning. As a result of a change of teachers, Boyle left Eton in 1638 to be privately tutored. In 1639 he went to Geneva, where he studied mathematics; his devotion to religion, so he tells us in his fragment of an autobiography, An Account of Philaretus during His Minority, dates from this same period. A visit to Florence in 1641–1642 introduced him to Galileo Galilei's ideas and confirmed him in his hostility to Roman Catholicism. His return to England was delayed by a crisis in his father's affairs. When Boyle was free to return to England in 1644, his father was dead and he had inherited the manor of Stalbridge in Dorsetshire.

Boyle stayed at first in London with his favorite sister, Lady Ranelagh, whose house was a center of intellectual life. There he met Samuel Hartlib (d. 1670?), an enthusiastic educator and intellectual middleman, through whom Boyle was brought in touch with the burgeoning scientific activities of London. In Boyle's correspondence with Hartlib there are several references to their membership in an "Invisible College"; this has generally been identified by biographers with the Gresham's College group out of which the Royal Society was to develop. The "Invisible College" Boyle referred to, however, would seem rather to have been an independent group centering on Hartlib and having an interest in social and educational reform as well as in science.

From 1645 until 1652 Boyle lived in retirement at Stalbridge, remote from the political upheavals of the times. He was still essentially a dilettante, interesting himself—but not too seriously—in chemistry, writing theological tracts of a highly moral character, and composing what was perhaps the first religious novel, Seraphic Love (1648). In 1652–1653 he visited his Irish estates; unable to obtain materials for chemical experiments, he studied anatomy under William Petty. The interest in biological processes thus engendered remained with him. In bad health from early manhood, he was particularly interested in the application of chemical methods to the cure of disease and was a diligent collector of prescriptions.

The Commonwealth had appointed a number of London scientists to posts at Oxford; in 1654 Boyle accepted an invitation from John Wilkins to make his home there. Now his serious career as a scientist began. He built a laboratory and employed a number of research assistants, in particular Robert Hooke (1635–1703), later to be curator of experiments at the Royal Society. With Hooke's help, Boyle constructed a greatly improved air pump, experiments with which provided the groundwork for Boyle's first and most important scientific work: New Experiments Physico-Mechanical touching the Spring of the Air and Its Effects (1660). Following up the work of Galileo and Evangelista Torricelli, Boyle demonstrated that air has both weight and elasticity and that the phenomena that had traditionally been ascribed to an anthropomorphically conceived "horror of a vacuum" were, in fact, a product of the air's elasticity.

His conclusions created an immediate stir but were not universally accepted. Boyle was criticized on philosophical grounds by Thomas Hobbes, Henry More, and the Jesuit Franciscus Linus (1595–1675), to all of whom he replied in detail. In the course of his reply to Linus, Boyle formulated what is known as Boyle's law. (On the Continent it is called Mariotte's law, Mariotte having confirmed it in 1676.) In the years that followed, Boyle took part in the meetings of the embryonic Royal Society at Oxford, conducted and published a great many experiments, corresponded voluminously with most of the leading thinkers of Europe, studied Oriental languages, actively supported the distribution of the Bible in foreign parts—becoming for that purpose a governor of the Corporation for the Spread of the Gospel to New England and a director of the East India Company—and wrote a considerable number of scientific, philosophic, and theological treatises. After the Restoration most of his scientific friends returned to London; Boyle left Oxford for London in 1668 and lived in Lady Ranelagh's household until her death. He died a week later.

Science and Philosophy

Boyle was profoundly influenced by Francis Bacon's conception of science; much of his published work consists of what Bacon called "histories"—systematic accounts of such qualities as color, firmness, and coldness as they appear under a variety of circumstances. His Spring of the Air was the first scientific paper of the modern type. He encouraged scientists to write relatively brief experimental "essays" rather than general treatises. His Animadversions upon Mr. Hobbes' Problemata de Vacuo (published in Boyle's Tracts, 1674) emphasized the fruitlessness of a priori philosophical reasoning—what Boyle called "book philosophy"—about issues that could be settled only by experiment.

But it is wrong to suppose that Boyle was an opponent of theorizing. He discusses the place of theory in science in his proemial essay to Certain Physiological Essays and other Tracts (1661). Scientists, he says, should "set themselves diligently to make experiments and collect observations, without being over forward to establish principles and axioms." Theories ought never to be taken as final; they should be thought of as "the best we have but capable of improvement." Nevertheless, it is the scientist's task to develop theories that are as clear, as simple, and as comprehensive as possible—a point that particularly emerges in Boyle's essay "About the Grounds of the Mechanical Hypothesis" (published in The Excellency of Theology, 1674).

Indeed, it was Boyle's main object "to beget a good understanding between the chemists and the mechanical philosophers, who have hitherto been too little acquainted with each other's learning." The corpuscular theory, which Pierre Gassendi had revived, suffered, Boyle thought, in the eyes of practical chemical experimentalists because so little had been done to test it. Theorists had been accustomed to illustrate their theories rather than to test them. On the other side, the work of the chemists had been ignored by physical theorists, largely because it had been associated with theories of a totally inadequate kind.

Doctrine of Matter

Boyle's The Sceptical Chemist (1661) is mainly concerned with demonstrating the unsatisfactory character of the standard chemical theories. It is written in the form of a dialogue in which the main speaker, Carneades, attacks not only the traditional theory of elements but also the alchemical theories that had been proposed by Paracelsus and Jan van Helmont. None of these theories, Boyle argued, can be reconciled with experiment, unless they are interpreted in so vague and symbolic a manner as to make them scientifically worthless. As an alternative, he set up the corpuscular theory. It is sometimes said that he also so redefined "elements" as to prepare the way for the modern doctrine of elements; but that is a mistaken interpretation. Indeed, what his chemistry lacked was precisely this modern conception of elements. That is why he was still able to believe in the possibility of alchemical transmutations. In 1689 he secured the repeal of Henry IV's statute against "multiplying gold."

In a sense, however, Boyle's work was too advanced theoretically. Not enough was known about chemical substances to enable the corpuscular theory to be effectively applied in chemistry. Although, in trying to bring together physics and chemistry and chemistry and biology, Boyle anticipated the long-range development of science, the program that he laid down for chemistry was one that for the moment no one knew how to fulfill; the immediate effect may well have been to hold back the development of chemistry. Boyle conceded, it is true, that explanations referring to perceptible properties rather than to the behavior of corpuscles are, at a certain level, perfectly satisfactory; but the general effect of his work was to discourage explanations of the only sort that chemists were actually in a position to offer. His own writings abound in interesting theoretical suggestions—in his General History of the Air (1692), for example, he anticipated the kinetic theory of gases—but for a very long time they had to remain no more than suggestions. Although Boyle's actual contributions to science are very few in number, the range of his anticipations is remarkable. He had set out to make chemistry respectable; he had succeeded, many chemists thought, only at the cost of turning it into physics.

Primary and Secondary Qualities

Boyle exerted an important influence on philosophy by lending the authority of a practicing scientist to the corpuscular theory of matter and the associated doctrine of primary and secondary qualities. In The Experimental History of Colours (1663), Boyle sets out to demonstrate that color is a "secondary quality" (his own terminology). Objects give rise to sensations of color, he tries to show, not because they are themselves colored but because the structure of their corpuscles modifies light in a special way. The word color is most properly applied, he argues, to the modified light that "strikes upon the organ of sight and so causes that sensation we call colour"; if we say that bodies themselves are colored, this can mean no more than that, by virtue of "a certain disposition of the superficial particles," they are capable of refracting or reflecting light.

This thesis is generalized in The Origin of Forms and Qualities according to the Corpuscular Philosophy (1666), in which the theory of qualities, which John Locke was to rely upon in his Essay concerning Human Understanding, is set forth in detail and contrasted with the Scholastic doctrine of substantial forms. The qualities of a material object, Boyle argues, consist of "the size, shape and motion or rest of its component particles, together with that texture of the whole which results from their being so contrived as they are." These primary qualities of objects, operating upon the "peculiar texture" of a sensory organ, "occasion ideas in us."

Science and Religion

The corpuscular philosophy had generally been associated with atheism. Boyle sets out to show that "by being addicted to experimental philosophy a man is rather assisted than indisposed to be a good Christian" (The Christian Virtuoso, 1690). His views about the relation between God and Nature, however, are by no means clear. In "An Hydrostatical Discourse Occasioned by Some Objections of Dr. Henry More," included in Tracts (1672), Boyle strongly opposes More's view that mechanical principles cannot explain the phenomena of pressure or any other physical phenomena. We do not need, he says, to have recourse to More's "incorporeal creatures"; mechanism is enough. Yet, at the same time, in Forms and Qualities he argues against René Descartes that we cannot account for the behavior of living organisms by supposing that they consist of particles on which God bestowed motion. We have to suppose, Boyle says, that the Creator not only set the world moving but also introduced into it "seminal seeds" that are responsible for the growth and propagation of animal organisms.

Again, in A Disquisition about the Final Causes of Natural Things (1688), he expresses his disagreement with those who would reject final causes completely, although he also argues that the scientist, in his day-to-day work, need pay no attention to anything except the size, shape, texture, and motion of particles. At times, indeed, as in The Excellency of Theology, or the Pre-eminence of the Study of Divinity above That of Natural Philosophy, Boyle's anxiety about the contemporary tendency to abandon theology in favor of scientific inquiries leads him into a skepticism about science. If theology has its obscurities, he argues, they are as nothing to the obscurities inherent in the scientific account of continuity or of the relation between mind and body. Revelation can tell us far more about the place of man in nature than can science. But the example of Boyle the scientist was more influential than the precepts of Boyle the theologian. His last gesture in favor of Christianity was to leave in his will a sum sufficient to endow lectures for the defense of Christianity against its opponents; his intellectual legacy, however, was the mechanical interpretation of the world that deism took as its starting point.

Bibliography

For a bibliography of Boyle's voluminous works, see John Farquhar Fulton, A Bibliography of the Honourable Robert Boyle, rev. 2nd ed. (Oxford: Clarendon Press, 1961). The only complete collected edition of Boyle's Works, edited by Thomas Birch, and with a still useful life by Birch that incorporates Boyle's Account of Philaretus, was published in London in five volumes in 1744 and in six volumes in 1772. The Sceptical Chemist is in the Everyman Library (London, 1911), and The Weight and Spring of the Air is in Vol. I of Harvard Case Histories in Experimental Science (Cambridge, MA: Harvard University Press, 1957), an anthology edited by James B. Conant.

For works on Boyle, see Edwin A. Burtt, The Metaphysical Foundations of Modern Physical Science (London: K. Paul, Trench, Trubner, 1925; rev. ed., 1932), Ch. 6, "Gilbert and Boyle"; Louis T. More, The Life and Works of the Hon. Robert Boyle (New York and London: Oxford University Press, 1944); Mitchell S. Fisher, Robert Boyle, Devout Naturalist (Philadelphia: Oshiver Studio Press, 1945); Marie Boas, Robert Boyle and Seventeenth Century Chemistry (Cambridge, U.K.: Cambridge University Press, 1958)—an excellent book; Richard S. Westfall, "Unpublished Boyle Papers relating to Scientific Method," in Annals of Science 12 (1) (March 1956): 63–73, and 12 (2) (June 1956): 103–117.

John Passmore (1967)

Encyclopedia of Philosophy