Roger Trigg is an emeritus professor of philosophy at the University of Warwick, a senior research fellow at the Ian Ramsey Centre, University of Oxford, and a long-standing member of St Cross College, Oxford. Trigg is a former Mind Association president and the founding president of the British Philosophical Association, representing all British philosophy. As the author of many books on central philosophical topics, he has opposed relativism in all its forms. His most recent book is Religious Diversity: Philosophical and Political Dimensions (Cambridge University Press, 2014), but much of his writing has focused on issues arising from the philosophy of science, including Rationality and Science (Wiley-Blackwell, 1993).

CHAPTER 1

Is Science the Sole Authority?

Metaphysics and Squirrels

IS "SCIENCE" MASTER in its own house, or does it depend on rational assumptions that it cannot itself prove? Perhaps it makes implicit presuppositions about the character of the world it studies, making such study possible. Many would vehemently deny that science needs anything that it cannot provide from its own resources. In other words, it needs no metaphysical framework in order to operate. It needs no philosophical foundation for its practices.

The very word "metaphysics" has raised many hackles over the last century. For some, it is a surrogate for theology — or at least needless obfuscation. In origin, the word referred to the subject of Aristotle's great work, as a name given to the book following his Physics, which dealt with the things of nature. In Greek, the word "meta" also carries with it the flavor of not just what lies after but of what lies beyond. Certainly at the beginning of Metaphysics, Aristotle relates the idea of wisdom to dealing with "the first principles and causes of things," and later connects this to the knowledge of those things that are universal, "which are the hardest for humans to know since they are furthest from the senses." For him, such metaphysics was "first philosophy," while the empirical discipline we now call science was "second philosophy." He did not see the sharp distinction between empirical work and philosophical understanding that the English language divides by talking of "science" in the one case but not in the other. For Aristotle, they were all forms of knowledge (episteme — the root of epistemology). Languages such as German even now do not make any radical distinctions between them. Philosophy is as much a form of Wissenschaft (science/knowledge) as physics. Much to the surprise of English philosophers, translating "international philosophy congresses" back to English becomes "scientific congresses."

"Science" is itself a word derived from the Latin word for "knowledge." It has become restricted to the empirical sciences, with the eighteenth-century notion of "natural philosophy" dismissed totally. That may be more than a quirk of language. It betrays an implicit suggestion that all human knowledge ultimately derives from our senses and suggests anything very far from such empirical investigation should be ignored, as it is not derived through human experience by observation and experiment.

American philosopher W.V. Quine, a giant of mid-twentieth-century thinking about science, denied the idea of "first philosophy." One of his influences was the philosophical tradition of American pragmatism. William James, for example, expressed pragmatists' impatience for excessively abstract thought, which they considered unrelated to the real world. James was one of the foremost proponents of pragmatism at the beginning of the twentieth century. Pragmatism exemplifies the attitude of those — and they are many — who, whether practicing scientists or not, rely on the fact that "science works." It has provided us with what was once unimaginable technology. While its products are not always benign, there is no doubt that modern science has given us the comfortable life that many enjoy. It has even taken men to the moon. Why do we need to worry about "first principles"? Is it not enough to see that, through the advance of science in theory and practice, we can control and predict the behavior of the physical world in ever more effective ways?

This attitude, with its "down-to-earth" and "no-nonsense" approach, has found abstractions irrelevant to the messy business of manipulating the physical world around us. James gave a celebrated illustration in defense of his view that "there can be no difference anywhere that doesn't make a difference some-where — no difference in abstract truth that doesn't express itself in a difference in concrete fact and in conduct consequent upon that fact." To use a favorite phrase of his, what is the "cash-value" of any statement? The illustration he gave came from a camping expedition when he found his companions arguing about what James took to be a metaphysical issue. His companions had seen a squirrel, and one of them had tried to follow it as it went, as squirrels will, around a tree trunk, keeping the trunk between the person and it. The squirrel went around the trunk, and so did the observer in pursuit, but he was not able to catch up with the squirrel. James put the issue this way: "The resultant metaphysical problem now is this: Does the man go round the squirrel or not?" The conclusion he drew was that it all depends on what "going round" means in practical terms. The dispute was in effect an idle one about the meaning of words, with the same practical consequences. There was no practical difference to be made whatever the conclusion. James insists that in the case of serious disputes "we ought to be able to show some practical difference."

As James himself points out, such pragmatism represents a familiar attitude in philosophy, what he terms the "empiricist attitude." The use of words has always to be constrained by what is within reach of our human experience, and differences in claims to truth have to make a difference in our experience and life. If everything remains the same — whatever we claim in metaphysics — that will demonstrate that our language is failing to get a grip on anything that matters. It is like a wheel turning that fails to turn anything else. The suggestion is that such idle talk is typical of metaphysics and illustrates the way it fails to get a proper grip on reality.

The Vienna Circle

Quine was fond in this context of referring to another image that came from Otto Neurath, a prominent member of the so-called "Vienna Circle," the group of philosophers that met in Vienna between the wars, which Quine attended at one time. Quine explained the image this way in his seminal book Word and Object: "Neurath has likened science to a boat, which if we are to rebuild it, we must rebuild plank by plank, while staying afloat in it." Whether it is in fact possible to rebuild a boat completely at sea may be disputed by boat builders, but the image is a powerful one. The idea is that one can change everything without any need to stand outside the boat. Science as an enterprise does not have to have any external philosophical or "metaphysical" base on which to rest. It can provide all the resources for development itself. We can remove one plank while standing on another, and in the same way, we can change one part of science and let it progress while still depending on another part.

The Vienna Circle had an immense influence, not least because its members were dispersed by the Second World War. In the English-speaking world, its "logical positivism" was popularized by A.J. Ayer's Language, Truth, and Logic. An Oxford philosopher, he taught what was known as "verificationism," the idea that not only the truth, but even the meaning of any statement that claimed non-logical truth, depended on our ability...