Francis Bacon (1561–1626), although his philosophy is in many ways unsatisfactory, has permanent importance as the founder of modern inductive method and the pioneer in the attempt at logical systematization of scientific procedure.
He was a son of Sir Nicholas Bacon, Lord Keeper of the Great Seal, and his aunt was the wife of Sir William Cecil, afterwards Lord Burghley; he thus grew up in the atmosphere of State affairs. He entered Parliament at the age of twenty-three, and became adviser to Essex. None the less, when Essex fell from favour he helped in his prosecution. For this he has been severely blamed: Lytton Strachey, for example, in his Elizabeth and Essex, represents Bacon as a monster of treachery and ingratitude. This is quite unjust. He worked with Essex while Essex was loyal, but abandoned him when continued loyalty to him would have been treasonable; in this there was nothing that even the most rigid moralist of the age could condemn.
In spite of his abandonment of Essex, he was never completely in favour during the lifetime of Queen Elizabeth. With James's accession, however, his prospects improved. In 1617 he acquired his father's office of Keeper of the Great Seal, and in 1618 he became Lord Chancellor. But after he had held this great position for only two years, he was prosecuted for accepting bribes from litigants. He admitted the truth of the accusation, pleading only that presents never influenced his decision. As to that, anyone may form his own opinion, since there can be no evidence as to the decisions that Bacon would have come to in other circumstances. He was condemned to a fine of £40,000, to imprisonment in the Tower during the king's pleasure, to perpetual banishment from Court and inability to hold office. This sentence was only very partially executed. He was not forced to pay the fine, and he was kept to the Tower for only four days. But he was compelled to abandon public life, and to spend the remainder of his days to writing important books.
The ethics of the legal profession, in those days, were somewhat lax. Almost every judge accepted presents, usually from both sides. Nowadays we think it atrocious for a judge to take bribes, but even more atrocious, after taking them, to decide against the givers of them. In those days, presents were a matter of course, and a judge showed his 'virtue' by not being influenced by them. Bacon was condemned as an incident in a party squabble, not because he was exceptionally guilty. He was not a man of outstanding moral eminence, like his forerunner Sir Thomas More, but he was also not exceptionally wicked. Morally, he was an average man, no better and no worse than the bulk of his contemporaries.
After five years spent in retirement, he died of a chill caught while experimenting on refrigeration by stuffing a chicken full of snow.
Bacon's most important book, The Advancement of Learning, is in many ways remarkably modern. He is commonly regarded as the originator of the saying 'Knowledge is power', and though he may have had predecessors who said the same thing, he said it with new emphasis. The whole basis of his philosophy was practical: to give mankind mastery over the forces of nature by means of scientific discoveries and inventions. He held that philosophy should be kept separate from theology, not intimately blended with it as in scholasticism. He accepted orthodox religion; he was not the man to quarrel with the government on such a matter. But while he thought that reason could show the existence of God, he regarded everything else in theology as known only by revelation. Indeed he held that the triumph of faith is greatest when to the unaided reason a dogma appears most absurd. Philosophy, however, should depend only upon reason. He was thus an advocate of the doctrine of 'double truth', that of reason and that of revelation. This doctrine had been preached by certain Averroists in the thirteenth century, but had been condemned by the Church. The 'triumph of faith' was, for the orthodox, a dangerous device. Bayle, in the late seventeenth century, made ironical use of it, setting forth at great length all that reason could say against some orthodox belief, and then concluding 'so much the greater is the triumph of faith in nevertheless believing'. How far Bacon's orthodoxy was sincere it is impossible to know.
Bacon was the first of the long line of scientifically minded philosophers who have emphasized the importance of induction as opposed to deduction. Like most of his successors, he tried to find some better kind of induction than what is called 'induction by simple enumeration'. Induction by simple enumeration may be illustrated by a parable. There was once upon a time a census officer who had to record the names of all householders in a certain Welsh village. The first that he questioned was called William Williams; so were the second, third, fourth…. At last he said to himself: 'This is tedious; evidently they are all called William Williams. I shall put them down so and take a holiday.' But he was wrong; there was just one whose name was John Jones. This shows that we may go astray if we trust too implicitly to induction by simple enumeration.
Bacon believed that he had a method by which induction could be made something better than this. He wished, for example, to discover the nature of heat, which he supposed (rightly) to consist of rapid irregular motions of the small parts of bodies. His method was to make lists of hot bodies, lists of cold bodies, and lists of bodies of varying degrees of heat. He hoped that these lists would show some characteristic always present in hot bodies and absent in cold bodies, and present in varying degrees in bodies of different degrees of heat. By this method he expected to arrive at general laws, having, in the first instance, the lowest degree of generality. From a number of such laws he hoped to reach laws of the second degree of generality, and so on. A suggested law should be tested by being applied in new circumstances; if it worked in these circumstances it was to that extent confirmed. Some instances are specially valuable because they enable us to decide between two theories, each possible as far as previous observations are concerned; such instances are called 'prerogative' instances.
Bacon not only despised the syllogism, but undervalued mathematics, presumably as insufficiently experimental. He was virulently hostile to Aristotle, but thought very highly of Democritus. Although he did not deny that the course of nature exemplifies a divine purpose, he objected to any admixture of teleological explanation in the actual investigation of phenomena; everything, he held, should be explained as following necessarily from efficient causes.
He valued his method as showing how to arrange the observational data upon which science must be based. We ought, he says, to be neither like spiders, which spin things out of their own insides, nor like ants, which merely collect, but like bees, which both collect and arrange. This is somewhat unfair to the ants, but it illustrates Bacon's meaning.
One of the most famous parts of Bacon's philosophy is his enumeration of what he calls 'idols', by which he means bad habits of mind that cause people to fall into error. Of these he enumerates four kinds. 'Idols of the tribe' are those that are inherent in human nature; he mentions in particular the habit of expecting more order in natural phenomena than is actually to be found. 'Idols of the cave' are personal prejudices, characteristic of the particular investigator. 'Idols of the market-place' are those that have to do with the tyranny of words. 'Idols of the theatre' are those that have to do with received systems of thought; of these, naturally, Aristotle and the scholastics afforded him the most noteworthy instances.
Although science was what interested Bacon, and although his general outlook was scientific, he missed most of what was being done in science in his day. He rejected the Copernican theory, which was excusable so far as Copernicus himself was concerned, since he did not advance any very solid arguments. But Bacon ought to have been convinced by Kepler, whose New Astronomy appeared in 1609. Bacon appears not to have known of the work of Vesalius, the pioneer of modern anatomy, though he admired Gilbert, whose work on magnetism brilliantly illustrated inductive method. Surprisingly, he seemed unconscious of the work of Harvey, although Harvey was his medical attendant. It is true that Harvey did not publish his discovery of the circulation of the blood until after Bacon's death, but one would have supposed that Bacon would have been aware of his researches. Harvey had no very high opinion of him, saying 'he writes philosophy like a Lord Chancellor'. No doubt Bacon could have done better if he had been less concerned with worldly success.
Bacon's inductive method is faulty through insufficient emphasis on hypothesis. He hoped that mere orderly arrangement of data would make the right hypothesis obvious, but this is seldom the case. As a rule, the framing of hypotheses is the most difficult part of scientific work, and the part where great ability is indispensable. So far, no method has been found which would make it possible to invent hypotheses by rule. Usually some hypothesis is a necessary preliminary to the collection of facts, since the selection of facts demands some way of determining relevance. Without something of this kind, the mere multiplicity of facts is baffling.
The part played by deduction in science is greater than Bacon supposed. Often, when a hypothesis has to be tested, there is a long deductive journey from the hypothesis to some consequence that can be tested by observation. Usually the deduction is mathematical, and in this respect Bacon underestimated the importance of mathematics in scientific investigation.
The problem of induction by simple enumeration remains unsolved to this day. Bacon was quite right in rejecting simple enumeration where the details of scientific investigation are concerned, for in dealing with details we may assume general laws on the basis of which, so long as they are taken as valid, more or less cogent methods can be built up. John Stuart Mill framed four canons of inductive method, which can be usefully employed so long as the law of causality is assumed; but this law itself, he had to confess, is to be accepted solely on the basis of induction by simple enumeration. The thing that is achieved by the theoretical organization of science is the collection of all subordinate inductions into a few that are very comprehensive—perhaps only one. Such comprehensive inductions are confirmed by so many instances that it is thought legitimate to accept, as regards them, an induction by simple enumeration. This situation is profoundly unsatisfactory, but neither Bacon nor any of his successors have found a way out of it.