Methods for a New Philosophy: Bacon and Descartes

René Descartes and Sir Francis Bacon

Advances in the new sciences eventually became concentrated in northwest Europe. Sir Francis Bacon (1561–1626) and René Descartes (deh-KAHRT) loom especially large in this development, setting out the methods or the rules that should govern modern science.

“Knowledge is power.” This phrase is Bacon’s and captures the new confidence in the potential of human thinking. Bacon trained as a lawyer, served in Parliament, and was briefly the lord chancellor to James I of England. His abiding concern was with the assumptions, methods, and practices of natural philosophy. The authority of the ancients should not constrain modern thinkers, and deference to accepted doctrines could block innovation or obstruct understanding. Pursuing knowledge did not mean thinking abstractly and leaping to conclusions; it meant observing, experimenting, and confirming ideas. If thinkers will be “content to begin with doubts,” Bacon wrote, “they shall end with certainties.” We thus associate Bacon with the gradual separation of scientific investigation from philosophical argument.

In inductive reasoning, the scientist amasses many observations and then draws general conclusions or proposes theories on the basis of these data

Bacon advocated an inductive approach to knowledge: amassing evidence from many discrete observations to draw general conclusions. In Bacon’s view, many philosophical errors arose from beginning with assumed first principles (see Competing Viewpoints on pages 562–63). The traditional view of the cosmos, for instance, rested on the principles of a prime mover and the perfection of circular motion for the planets and the stars. The inductive method required accumulating data (as Tycho had done) and then, after careful review and experiment, drawing appropriate conclusions about the motions of heavenly bodies. Bacon argued that scientific knowledge was best tested through the cooperative efforts of scientists performing experiments that could be repeated and verified. In this practical sense, his work anticipated the modern research university. At the same time, he also connected the new science with the expansion of European colonialism. The title page of his work Novum Organum (1620), depicts bold ships sailing beyond the Straits of Gibraltar, formerly the limits of the West, into the open sea. Through such imagery, Bacon’s vision of science as “discovery” also became incorporated into a political vision of expanding European power.

In René Descartes’s (1596–1650) Discourse on Method (1637), for which he is best known, he recounted his dismay at the “strange and unbelievable” theories he encountered in his traditional education. His first response, as he described it, was to doubt everything he had ever known or been taught. His rule was “never to receive anything as a truth which [he] did not clearly know to be such.” He took the human ability to think as his point of departure, summed up in his famous and enigmatic Je pense, donc je suis, later translated into Latin as Cogito, ergo sum and into English as “I think, therefore I am.” As the phrase suggests, Descartes’s doubting led (quickly, by our standards) to self-assurance and truth: the thinking individual existed, reason existed, God existed. For Descartes, then, doubt was a ploy, a strategy that he used to defeat skepticism. Certainty, not doubt, was the centerpiece of the philosophy he bequeathed to his followers.

In deductive reasoning, the scientist begins with one self-evident principle and uses reason to derive other truths from this foundation

Unlike Bacon, however, Descartes emphasized deductive reasoning, proceeding logically from one known certainty to another. “So long as we avoid accepting as true what is not so,” he wrote in Discourse on Method, “and always preserve the right order of deduction of one thing from another, there can be nothing too remote to be reached in the end, or too well hidden to be discovered.” For Descartes, mathematical thought expressed the highest standards of reason, and his work contributed greatly to the authority of mathematics as a model for scientific reasoning.

Descartes’s mechanical philosophy

Descartes made a particularly forceful statement for mechanism, a view of the world shared by Bacon and Galileo and one that came to dominate seventeenth-century scientific thought. As the name suggests, mechanical philosophy proposed to consider nature as a machine. It rejected the traditional Aristotelian distinction between the works of humans and those of nature, and the view that nature, as God’s creation, necessarily belonged to a different—and higher—order. In the new picture of the universe that was emerging from the discoveries and writings of the early seventeenth century, it seemed that all matter was composed of the same material and that all motion obeyed the same laws. Descartes sought to explain everything, including the human body, mechanically. As he put it firmly, “There is no difference between the machines built by artisans and the diverse bodies that nature alone composes.” Nature operated according to regular and predictable laws and thus was accessible to human reason. This belief guided and inspired the scientific work of the seventeenth century.

COMPETING VIEWPOINTS

The New Science and the Foundations of Certainty

Francis Bacon (1561–1626) and René Descartes (1596–1650) were both enthusiastic supporters of science in the seventeenth century, but they differed in their opinions regarding the basis for certainty in scientific argumentation. Bacon’s inductive method emphasized the gathering of particular observations about natural phenomena, which he believed could be used as evidence to support more-general conclusions about causes, regularity, and order in the natural world. Descartes, on the other hand, defended a deductive method. He believed that certainty could be built only by reasoning from first principles that one knew to be true, and he was less certain of the value of evidence that came from the senses alone.

Aphorisms from Novum Organum

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XXXI It is idle to expect any advancement in science from the super-inducing and engrafting of new things upon old. We must begin anew from the very foundations, unless we would revolve forever in a circle with mean and contemptible progress. . . .

XXXVI One method of delivery alone remains to us which is simply this: we must lead men to the particulars themselves, and their series and order; while men on their side must force themselves for a while to lay their notions by and begin to familiarize themselves with facts. . . .

XLV The human understanding of its own nature is prone to suppose the existence of more order and regularity in the world than it finds. And though there be many things in nature which are singular and unmatched, yet it devises for them parallels and conjugates and relatives which do not exist. Hence the fiction that all celestial bodies move in perfect circles. . . . Hence too the element of fire with its orb is brought in, to make up the square with the other three which the sense perceives. . . . And so on of other dreams. And these fancies affect not dogmas only, but simple notions also. . . .

XCV Those who have handled sciences have been either men of experiment or men of dogmas. The men of experiment are like the ant, they only collect and use; the reasoners resemble spiders, who make cobwebs out of their own substance. But the bee takes a middle course: it gathers its material from the flowers of the garden and of the field, but transforms and digests it by a power of its own. Not unlike this is the true business of philosophy; for it neither relies solely or chiefly on the powers of the mind, nor does it take the matter which it gathers from natural history and mechanical experiments and lay it up in the memory whole . . . but lays it up in the understanding altered and digested. Therefore, from a closer and purer league between these two faculties, the experimental and the rational (such as has never yet been made), much may be hoped. . . .

Source: Michael R. Matthews, ed., The Scientific Background to Modern Philosophy: Selected Readings (Indianapolis, IN: 1989), pp. 47–48, 50–52.

From Discourse on Method

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Just as a great number of laws is often a pretext for wrong-doing, with the result that a state is much better governed when, having only a few, they are strictly observed; so also I came to believe that in the place of the great number of precepts that go to make up logic, the following four would be sufficient for my purposes, provided that I took a firm but unshakeable decision never once to depart from them.

The first was never to accept anything as true that I did not incontrovertibly know to be so; that is to say, carefully to avoid both prejudice and premature conclusions; and to include nothing in my judgments other than that which presented itself to my mind so clearly and distinctly, that I would have no occasion to doubt it.

The second was to divide all the difficulties under examination into as many parts as possible, and as many as were required to solve them in the best way.

The third was to conduct my thoughts in a given order, beginning with the simplest and most easily understood objects, and gradually ascending, as it were step by step, to the knowledge of the most complex; and positing an order even on those which do not have a natural order of precedence.

The last was to undertake such complete enumerations and such general surveys that I would be sure to have left nothing out.

The long chain of reasonings, every one simple and easy, which geometers habitually employ to reach their most difficult proofs had given me cause to suppose that all those things which fall within the domain of human understanding follow on from each other in the same way, and that as long as one stops oneself taking anything to be true that is not true and sticks to the right order so as to deduce one thing from another, there can be nothing so remote that one cannot eventually reach it, nor so hidden that one cannot discover it. . . .

[B]ecause I wished . . . to concentrate on the pursuit of truth, I came to think that I should . . . reject as completely false everything in which I could detect the least doubt, in order to see if anything thereafter remained in my belief that was completely indubitable. And so, because our senses sometimes deceive us, I decided to suppose that nothing was such as they lead us to imagine it to be. And because there are men who make mistakes in reasoning, even about the simplest elements of geometry, and commit logical fallacies, I judged that I was as prone to error as anyone else, and I rejected as false all the reasoning I had hitherto accepted as valid proof. Finally, considering that all the same thoughts which we have while awake can come to us while asleep without any one of them then being true, I resolved to pretend that everything that had ever entered my head was no more true than the illusions of my dreams. But immediately afterwards I noted that, while I was trying to think of all things being false in this way, it was necessarily the case that I, who was thinking them, had to be something; and observing this truth: I am thinking therefore I exist, was so secure and certain that it could not be shaken by any of the most extravagant suppositions of the sceptics, I judged that I could accept it without scruple, as the first principle of the philosophy I was seeking.

Source: René Descartes, A Discourse on the Method, trans. Ian Maclean (New York: 2006), pp. 17–18, 28.

Questions for Analysis

Descartes’s idea of certainty depended on a “long chain of reasonings” that departed from certain axioms that could not be doubted, and rejected evidence from the senses. What science provided him with the model for this idea of certainty? What was the first thing that he felt he could be certain about? Did he trust his senses?
Bacon’s idea of certainty pragmatically sought to combine the benefits of sensory knowledge and experience (gathered by “ants”) with the understandings arrived at through reason (cobwebs constructed by “spiders”). How would Descartes have responded to Bacon’s claims? According to Bacon, was Descartes an ant or a spider?
What do these two thinkers have in common?

An illustration of Descartes to show the optical properties of human eye. — FROM RENÉ DESCARTES, *L’HOMME* (1729; ORIGINALLY PUBLISHED AS *DE HOMINE*, 1662). Descartes’s interest in the body as a mechanism led him to suppose that physics and mathematics could be used to understand all aspects of human physiology, and his work had an important influence on subsequent generations of medical researchers. In this illustration, Descartes depicts the optical properties of the human eye. › How might such a mechanistic approach to human perception have been received by proponents of Baconian science who depended so much on the reliability of human observations?

THE POWER OF METHOD AND THE FORCE OF CURIOSITY: SEVENTEENTH-CENTURY EXPERIMENTERS

For nearly a century after Bacon and Descartes, most of England’s natural philosophers were Baconian, and most of their colleagues in France, Holland, and elsewhere in northern Europe were Cartesians (followers of Descartes). The Cartesians turned toward mathematics and logic. Descartes himself pioneered analytical geometry. Blaise Pascal (1623–1662) worked on probability theory and invented a calculating machine before applying his intellectual skills to theology. A Dutch Cartesian, Baruch Spinoza (1632–1677), applied geometry to ethics and believed he had proved that the universe was composed of a single substance that was both God and nature.

English experimenters pursued a different course. They began with practical research, putting the alchemist’s tool, the laboratory, to new uses. They also sought a different kind of conclusion: empirical laws or provisional generalizations based on evidence rather than absolute statements of deductive truth. Among the many English laboratory scientists of this era were the physician William Harvey (1578–1657), the chemist Robert Boyle (1627–1691), and the inventor and experimenter Robert Hooke (1635–1703).

Harvey observed human and animal bodies and explained that blood circulated through the arteries, heart, and veins. Boyle’s experiments established a law (known as Boyle’s law) showing that at a constant temperature the volume of a gas decreases in proportion to the pressure placed on it. Hooke introduced the microscope to the experimenter’s tool kit. The compound microscope had been invented in Holland early in the seventeenth century, but it was not until the 1660s that Hooke and others demonstrated its potential by using it to study the cellular structure of plants. Like the telescope before it, the microscope revealed an unexpected dimension of material phenomena. Examining even the most ordinary objects revealed detailed structures of perfectly connected smaller parts, and this persuaded many that with improved instruments they would uncover even more of the world’s intricacies.

A close-up drawing of a fly’s head, showing compound lenses in the eye. — ROBERT HOOKE’S *MICROGRAPHIA.* Hooke’s diagram of a fly’s eye as seen through a microscope seemed to reveal just the sort of intricate universe the mechanists predicted. › Compare this image with that of Galileo’s sunspots (page 553). What do these two images have in common?

The microscope also provided what many regarded as new evidence of God’s existence. The minute structure of a living organism, when viewed under a microscope, corresponded to its purpose and testified not only to God’s existence but also to God’s wisdom. The mechanical philosophy did not exclude God but in fact could be used to confirm his presence. If the universe was a clock, there must be a clockmaker. Hooke himself declared that only imbeciles would believe that what they saw under the microscope was “the production of chance” rather than of God’s creation.

THE STATE, SCIENTIFIC ACADEMIES, AND WOMEN SCIENTISTS

Seventeenth-century state building (see Chapter 14) helped secure the rise of science. In 1660, the newly crowned King Charles II granted a group of natural philosophers a royal charter to establish the Royal Society of London, for the “improvement of natural knowledge.” The Royal Society would pursue Bacon’s goal of collective research, in which members would conduct formal experiments, record the results, and share them with other members. These members would in turn study the methods and attempt to reproduce the experiment. This enterprise would give England’s natural philosophers a common sense of purpose and a system to reach reasoned, gentlemanly agreement on “matters of fact.” By separating systematic scientific research from the dangerous language of politics and religion that had marked the English Civil War, the Royal Society could help restore a sense of order and invite rational discussion in intellectual life.

The French Academy of Sciences was founded in 1666, and it was also tied to seventeenth-century state building, in this case, Bourbon absolutism (see Chapter 15). Royal societies, devoted to natural philosophy as a collective enterprise, provided a state- (or prince-) sponsored framework for science, and an alternative to the important but uncertain patronage of religious (and largely conservative, Aristotelian) universities. Scientific societies reached rough agreements about what constituted legitimate research; they established the modern scientific custom of crediting discoveries to those who were the first to publish results; and they enabled the easier exchange of information and theories across national boundaries. Science began to take shape as a discipline.

The early scientific academies did not have explicit rules barring women, but with few exceptions they consisted only of men. This did not mean that women did not practice science, though their participation in scientific research and debate remained controversial. In some cases, the new science could itself become a justification for women’s inclusion, as when the Cartesian philosopher François Poullain de la Barre used anatomy to declare in 1673 that “the mind has no sex.” Since women possessed the same physical senses as men and the same nervous systems and brains, Poullain asserted that they might occupy the same roles in society as men. In fact, historians have discovered more than a few women who taught at European universities in the sixteenth and seventeenth centuries, above all in Italy. Elena Cornaro Piscopia received her doctorate in philosophy in Padua in 1678, the first woman to do so. Laura Bassi became a professor of physics at the University of Bologna after receiving her doctorate there in 1733, and on the merits of her exceptional contributions to mathematics, she became a member of the Academy of Science in Bologna. Her papers—such as “On the Compression of Air” (1746), “On the Bubbles Observed in Freely Flowing Fluid” (1747), and “On Bubbles of Air That Escape from Fluids” (1748)—gained her a stipend from the academy.

Italy appears to have been an exception in allowing women to win formal recognition for their education and research in established institutions. Elsewhere, elite women could educate themselves by associating with learned men. The aristocrat Margaret Cavendish (1623–1673), a natural philosopher in England, gleaned the information necessary to start her career from her family and their friends, a network that included Thomas Hobbes and René Descartes. These connections were not enough to overcome the isolation she felt working in a world of letters that was still largely the preserve of men, but this did not prevent her from developing her own speculative natural philosophy and using it to critique those who would exclude her from scientific debate. The “tyrannical government” of men over women, she wrote, “hath so dejected our spirits, that we are become so stupid, that beasts being but a degree below us, men use us but a degree above beasts. Whereas in nature we have as clear an understanding as men, if we are bred in schools to mature our brains.”

A drawing of a woman and her husband standing near an instrument to measure angles to observe the timing of Venus’s passage. — *OBSERVING THE TRANSIT OF VENUS* (1673). Elisabetha (1647–1693) and Johannes Hevelius (1611–1687) believed that precise observations about the timing of Venus’s passage across the face of the sun when observed from different parts of the earth could be used to calculate the distance from the earth to the sun. This husband-and-wife astronomy team worked together on many projects.

The construction of observatories in private residences enabled some women living in such homes to work their way into the growing field of astronomy. Between 1650 and 1710, some 14 percent of German astronomers were women, the most famous of whom was Maria Winkelmann (1670–1720). Winkelmann had collaborated with her husband, Gottfried Kirch, in his observatory; by the time of his death, she had already done significant work, including discovering a comet and preparing calendars for the Berlin Academy of Sciences. As Kirch’s widow, she petitioned the academy to allow her to take her husband’s place in that prestigious body—but she was rejected. Gottfried Leibniz, the academy’s president, explained, “Already during her husband’s lifetime the society was burdened with ridicule because its calendar was prepared by a woman. If she were now to be kept on in such capacity, mouths would gape even wider.” In spite of this rejection, Winkelmann continued to work as an astronomer, training both her son and two daughters in the discipline.

Like Winkelmann, the entomologist Maria Sibylla Merian (1647–1717) was able to carve out a space for her scientific work by exploiting the precedent of guild women who learned their trades in family workshops. Merian was a daughter of an engraver and illustrator in Frankfurt and served as his informal apprentice before beginning her own career as a scientific illustrator, specializing in detailed engravings of insects and plants. Traveling to the Dutch colony of Surinam, Merian supported herself and her two daughters by selling exotic insects and animals she collected and brought back to Europe. She fought the colony’s sweltering climate and malaria to publish her most important scientific work, Metamorphosis of the Insects of Surinam, which detailed the life cycles of Surinam’s insects in sixty ornate illustrations. Merian’s Metamorphosis was well received in her time; in fact, Peter I of Russia proudly displayed her portrait and books in his study.

Francis Bacon: (1561–1626) British philosopher and scientist who pioneered the scientific method and inductive reasoning.
René Descartes: (1596–1650) French philosopher and mathematician who emphasized the use of deductive reasoning.
Royal Society: British society founded to pursue collective research, giving English scientists a sense of common purpose as well as a system for reaching a consensus on facts.
Academy of Sciences: French institute of scientific industry founded in 1666 by Louis XIV. France’s statesmen exerted control over the academy and sought to share in the rewards of any discoveries its members made.
Laura Bassi: (1711–1778) Admitted to the Academy of Science in Bologna for her work in mathematics, which made her one of the few women to be accepted into a scientific academy in the seventeenth century.
Margaret Cavendish: (1623–1673) English natural philosopher who developed her own speculative natural philosophy. She used this philosophy to critique those who excluded her from scientific debate.
Maria Winkelmann: (1670–1720) German astronomer who discovered a comet and prepared calendars for the Berlin Academy of Sciences
Maria Sibylla Merian: (1647–1717) A scientific illustrator and an important early entomologist.
: A dismissive reference to Johannes Kepler’s 1602 “second law of planetary motion,” that all planets move in an ellipse, not a circle.
: Bacon describes how philosophers gather sensory knowledge and experience.
: Bacon describes deductive reasoners, who seek to produce complexity and nuance.
: These two camps of scientific reasoning.
: Descartes introduces skepticism here as an essential part of the scientific method.
: Proposing.
: Accounting for.
: Unlike Bacon, Descartes did not believe in the reliability of sensory observation.
: Often thought of as a “bottom–up” model of scientific thought, moving from the specific to the more general.
: Often thought of as a “top–down” model of scientific thought, moving from the more general to the more specific.
: A concise statement of a scientific principle.
: “New instrument” or “new method.”
: Bacon critiques Renaissance humanists and Aristotelian philosophers, who, according to Bacon, held too much confidence in Aristotle’s understanding of science
: Bacon is referring to ancient thinkers such as Aristotle.
: Individual observation.
: Not able to be denied or disputed.
: Using his perspective as the inventor of analytical geometry, in this passage Descartes applies mathematical problem–solving strategies to scientific, or philosophical, problems.
: A flaw in reasoning. Logical fallacies might be hastily made generalizations or circular arguments.
: While meditating the reliability of his conscious thoughts against those of his dreams, Descartes became acutely aware of his thought process. Descartes’s awareness of thinking was definitive proof to him that he existed.
: Not letting preconceived notions about situations cloud judgement.