History of Western Philosophy - Bertrand Russell [308]
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,