Jagdish Hattiangadi

Francis Bacon identified with Socrates in many ways. Socrates famously claimed that he knew nothing, but at least he knew that he knew nothing. He used his method of refutation, the elenchus, to show others who claimed to be wise that they did not know, not even that they did not know. Socrates also contended that though he was barren of knowledge, he could help others give birth to new knowledge by using his elenchus. In Plato’s Gorgias, the demanding conditions for affirming knowledge of general principles which are generated by exploiting an elenchus or a method of refutation are examined with care. Following Gregory Valstos, we find that it has apparently fatal difficulties. Plato, Aristotle, and later all philosophers concurred that no technique that depends only on refutation could be shown to lead to an affirmative knowledge of principle. Elenctic failure led to the problem of induction. Francis Bacon found a new wrinkle in the Socratic method, explained in the chapter, giving us a clever technique still in use in some of the best modern science.

Isaac Newton used experimental philosophy to extract his theory of light from geometrical discrepancies in the images of sunlight. He found that the image formed by light going through a round hole and a prism in a dark room is mathematically impossible. It should be round, like the aperture through which it comes into the room, but it is oblong. The image width is mathematically correct, but not the length. He shows that sunlight has rays that refract at different angles, each having a different color. The colors refract into circles, as mathematically predicted. But each color superimposes at a different height in the image, giving its oblong shape. From this experimental result, he derives a general theory of the colors and heterogeneity of all white light. His discovery resolved a great many problems of color, which formed a complex optical puzzle before his time. This case illustrates how the experimental method provides us with knowledge about phenomena, not just guesses that shed light on them. Neither the Cartesian way nor any other manner of hypothesis can offer unconditional knowledge. However, the hypothetico-deductive process remains helpful in science whenever the experimental philosophy has yet to render its verdict.

We can appreciate Francis Bacon’s method better if we collect his many remarks together than by carefully analyzing a few. Some suggest that he proposed the method of eliminative induction, i.e., refuting all hypotheses listed but one, which must be true. However, he knew those listed were not the only possible hypotheses, so eliminative induction cannot be his method. Other commentators think he was formulating a new chemical opinion of the world. He probably did hold such an opinion, but he tells us that his opinion is not his method, which is to find out what is the case, no matter anyone’s opinion, including his own. His comments on puzzles make his thoughts clearer if we gather them together with his other aphorisms. He writes that science is like a sphinx, letting you pass when you answer its riddle correctly. He compares science to cryptanalysis, seeking a way out of a labyrinth, or a game of hide and seek. If we put all this together, we can better understand his meaning—induction is puzzle-solving.

His Anglican theology shaped Francis Bacon’s new plan for science. Thrown out of Eden, he believed, Adam had lost all knowledge, even of morals and nature. Out of divine mercy, Adam’s progeny were offered biblical knowledge on conducting and saving ourselves (the Pentateuch), with universal love as our guide (the Gospel.) God did not instruct us how to acquire natural knowledge to regain our lost dominion over things but generously gave us the means to know it. We must find out for ourselves. Francis Bacon thought that the gift of many kinds of errors (Idols or Eidola) allows us to break through appearances to access hidden realities through a new elenchus. His elenchus was the cross-examination of nature. Moreover, Anglicanism allowed for this kind of free thought about nature, unlike the other orthodoxies. Though nominally Protestant, it restricted its teaching to the goal of salvation, laying no claim beyond it to discoveries of nature. Francis Bacon suggested that we pursue knowledge not for itself (which was Adam’s sin) but for the sake of Christian charity, to acquire new powers over nature and harness them to relieve human distress. But we could study nature skeptically only if prudently we kept our method away from faith, which was held safe by its confinement within the Church. Religion was confined to salvation, and skepticism was free to roam in all matters that were not divine.

The Baconian method had few followers at first. The attention of philosophers was soon riveted on Galileo Galilei, who had trained the telescope on the heavens and discovered many surprising things there. He championed the Copernican system of the planets, describing the earth as a moving planet. He also proposed a new conception of geometry, which underlies modern metaphysics, describing a mathematical universe through and through that undercut the ancient conception of a qualitative and finite cosmos. Together with these innovations, he proposed a new method of gaining knowledge, according to which we can know some mathematical principles as certainly as God knows them. However, our intensive knowledge is limited to a few Principles, whereas God’s is extensive and complete. In this chapter, we see how the problem of knowledge that Aristotle raised in his Posterior Analytics can be solved by a foundational method proposed by Galileo Galilei, using thought experiments and a reductio ad absurdum technique. Although Galileo Galilei’s remarks were suggestive and not systematically developed, they immensely influenced later natural philosophers, thus overshadowing Francis Bacon’s method for some time.

David Hume’s influential arguments against causal and inductive knowledge are presented below. Then, a powerful argument by Henri Poincare regarding principles of physics as true-by-convention is discussed next, followed by arguments for the underdetermination of theory by fact from Pierre Duhem—and later by Willard Quine. These are the difficulties we must meet. Francis Bacon’s induction did meet them, even before they were offered. The method is introduced and briefly outlined in this chapter, but not yet expounded.

The Great Instauration, a Baconian project, is a form of active fallibilism about natural knowledge. The practice is borrowed from Plato’s new form of skepticism. Meno challenged Socrates with a puzzle about his search for knowledge, which Plato solved by showing that Socrates, who claimed he knew nothing, nevertheless may have known accurate answers to his questions. Perhaps all our knowledge of affirmative principles is a recollection of what we know innately. Therefore, Socrates did not even know that he knew nothing, as he claimed! Later, this motto was adopted by some Academics in Plato’s school. Plato adopted the method of hypothesis in the Meno, which led him to practice active fallibilism—always question your best wisdom! If he endorsed a belief in one situation, he challenged it later in another. Plato’s account is incoherent in the end when applied to his fallibilism. But the clash may not arise explicitly if the situations of the conflicting statements do not coincide. Situational skepticism is not a solution, but the best Plato and his skeptical followers, the Academics, could have done without naming fallibilism as their doctrine.

René Descartes took up Galileo Galilei’s kinematic science and his foundational method in his Discourse on Method. He challenged ancient forms of skepticism with a simple argument. Since we are rational animals, i.e., able to distinguish true from false judgments, we must, therefore, have a natural ability to tell some statements as clearly true. We can and must derive principles of philosophy deductively from such clear truths, committing no error. Our new science will be infallibly true. In applying the method, he used a reductio ad absurdum argument. He began with an undoubtedly known premise, showing that I cannot doubt everything. When I try, I cannot doubt that I exist. From “I exist” as an imperfect being, he derived that a perfect God exists, from whose invariable nature he derived the basic principles of motion, which he published later in his The Principles of Philosophy. Some of these principles (of inertia and force) became fundamental laws of motion in physics. But he admitted in the sixth part of the Discourse a fundamental limitation of his method. Though certainly known, he claimed, the universal principles cannot be applied to particulars in the world without assuming hypothetical models. The Cartesian method’s main weakness was its reliance on fictional hypotheses as models of reality when compared with the Baconian that did not rely on fiction.

Since the interpretation of Francis Bacon’s method is new, it will need to be supported by his text. This chapter combines his entire method with key quotations from his writings. We begin with his rescue of secular thought in a religious environment. We note his recruitment of Socratic cross-examination of evidence. We review his idea of pursuing truth up the pyramid of knowledge. Like Plato’s Academy, science will remain actively fallible. At every stage, the point of gaining power over nature is for Christian charity. In this chapter, we will find the only explanation of the technological benefit of modern science in Francis Bacon’s notions. This chapter reflects themes from the rest of the book so we can appreciate how they fit together as a cohesive whole.

The foundational or mathematical method reduces to the method of hypothetical models when applied. René Descartes brilliantly used it to derive a new sine law of refraction. He suggested that light is pressure but conforms to the laws of motion. A model of colors gives us an analysis of the rainbow that was widely and rightly admired in his time. He derived many well-known color phenomena from his theory that colored light is a state of sunlight. A color is like a twist on a moving ball, which the retina feels when the light (ball) presses on it. He used multiple models to illustrate his many optical claims, comparing light to a rigid walking stick, to wine pressing down in a vat, and to a tennis ball moving on a path impeded at a surface.

Generating a puzzle of the right kind requires a special kind of natural history or account as background. It is a history of the nature of things. In many cases, the same kind of thing is noted in such a record. But the same nature will be found to be present here and absent there, or found varying in degrees. A thing can have only one invariable nature. A description of many is paradoxical. It offers up a puzzle to solve, to which many more are added. Building a natural history creates a great puzzle about a small area of study. The narrative is, therefore, a refutation of familiar claims to knowledge. It is important that the experiments refute the existing evidence and not a hypothesis. We adduce other (experimental) evidence that creates puzzles in an old-fashioned, self-consistent natural history. We preserve the puzzle in a journal. Solved puzzles are breakthroughs in finding a hidden model or latent schematism that makes sense of all the weird evidence.

From the Pyrrhonians, who recommended living by appearances, Francis Bacon learned how apparent knowledge is practical. If we can improve how reality appears, we can gain new power over nature. This idea is at the heart of his method of science. Pyrrhonians broke off from the Academy, for the first time forming a school proclaiming skepticism. They had to solve the problem of situational skepticism. Sextus Empiricus refused to endorse or deny any opinion about reality, assenting only to its appearances. Plato’s Academy had been accused of being impractical since they never wholeheartedly recommended a way of life, always doubting their best advice as less than knowledge (being actively fallible.) Pyrrhonians, mostly skeptical medical practitioners, countered that we do not need to follow philosophical opinions because we can live by appearances or how reality seems. If we stop fussing about what is really the case, we may get some ataraxia (peace of mind.) Francis Bacon took advantage of how appearances can be practically useful. He proposed making them even more practical by going beyond them to new knowledge of an underlying reality that gives us new powers over nature.

Early modern science is composed of two momentous philosophical innovations supplementing the Copernican hypothesis. Francis Bacon proposed a new epistemological method for deciphering reality faithfully behind discrepancies in its appearance. To succeed in this experimentally oriented task, he asks us to suspend all metaphysical judgment. Reflecting on the apparent indiscernibility of the earth’s motion, however, Galileo invented a dramatic new metaphysics: motion (the enigmatic “becoming” of ancient philosophy) is governed by the most perfectly understandable geometrical laws that are also the most fundamental in nature. Modern physics is unimaginable if it were not experimental and mathematical at once. Each of these new philosophical breakthroughs commanded our assent, it would seem, but they fit uncomfortably together.