Scientific truth is not the only truth out there

It is right for scientists to raise the Big Questions, but they are mistaken if they believe they can answer them all, argues Mary Warnock.

Science and philosophy were once indistinguishable. It is senseless to try to decide whether the pre-Socractic philosophers, especially the Milesians who taught in the 6th century BC, were scientists or philosophers; their theories were about the nature of the universe as a whole, seeking economical explanations of the nature of things.

It was abstract cosmology that they practised. They were concerned with the question "What there is?" And this led them to the, to our minds, more explicitly philosophical question: "What is the relation between what is and what appears?" Or, still more philosophically: "How can we claim to know anything?"

As the possibility of empirical observation increased, so more of the Big Questions split off from philosophy and became sciences on their own account - mathematics, physics, chemistry and, finally, biology. Indeed, many questions about perception, the nature of pain, our concept of personal identity and of consciousness itself may increasingly be approached these days through the science of neurophysiology.

Broadly, science seeks explanations for phenomena through evidence that can be verified or falsified. True, many scientific explanations are necessarily hypothetical, theory rather than fact; but every theory is rendered plausible or implausible by its relation to the way things are, what is open to observation.

Nevertheless, scientists, perhaps more than most people, dislike the idea of questions that cannot be answered. They may therefore be tempted to try to answer questions for which there can be no evidence one way or the other, or where it does not make any difference whether you answer yes or no. In some cases it may be the proper role of philosophy to insist that the meaning of such questions or proposed answers should be made clear and call scientists to heel.

Though philosophy is concerned with what there is in the world, just as science is, it is important to distinguish between scientific questions, legitimately raised and perhaps answered by scientists, and questions of value, where what is needed is not so much corroboration by evidence as judgement, which scientists may or may not be blessed with.

An illustration can be found in the issue of whether or not it is legitimate to use early human embryos for experimental purposes. When in-vitro fertilisation was first practised, and this question arose in framing the law, people used to ask "When does human life begin?" Though the question so posed looked like a scientific one, it was not. Sperm and eggs are both human and the subject of the biological sciences, therefore living entities. But the real question was what value ought to be attached to the collection of cells at the very beginning of its divisions. And this was a question of morality, not of science.

Of course moralists who sought to answer it had to be informed of the facts of embryonic development. But that moral judgements should be based on an understanding of the laws of nature does not entail that there is no difference between science and morality. Nor does it entail that morality is somehow unreal, simply because it is not science. Our valuing of things is not an optional extra: it is an essential function of all life, not just human life. It is only that human beings are brighter than other animals, and can talk about what they value, and set for themselves new aims and ideals. And this is how they become philosophers.

I do not believe there is any intrinsic limit to what science can do or the questions it can answer as long as these answers are genuinely capable of being based on evidence. Probably the boundaries of science are constantly being pushed back, perhaps at the expense of philosophy. If so, then it is right and salutary for scientists to raise the big questions and try to conquer new territory.

But scientists should beware of the temptation to set themselves up as sages, merely because they are scientists. They may or may not have the imaginative insight into the moral sentiments that should govern human behaviour; but they cannot claim that it is out of their science alone that such insight arises. If a scientist pretends to be able, by appeal to evidence, to answer a question about, say, what constitutes a moral evil, then the philosopher may step in to point out that morality cannot be merely a matter of evidence of harm. It must also rely on the kind of sentiments that lead us to shun certain forms of behaviour and try to teach others to shun them too.

Scientists must try to be dispassionate in their evaluations of evidence. Philosophers need not and cannot always disregard the emotional impact of the world on the human agents who inhabit it.

The imagination of the philosopher is different from that of the scientist, though both may be seeking for truth. But scientific truth is not the only sort there is.

Baroness Warnock, former mistress of Girton College, Cambridge, is a contributor to The THES book Big Questions in Science , published next week by Jonathan Cape, £15.99. Call 01454 617370 to order the book at the special price of £12.99.