Is science concerned with truth?

Mention the word truth to most scientists and they become nervous, twitchy, then dismissive and distinctly irritable. Truth, they will most likely reply, in a serious, no-nonsense, huffy and puffy way, is a subject for philosophers to argue over (Murray Gell-Mann has a doctor's prescription strictly forbidding him from engaging in philosophical debates). Truth is a metaphysical term, or, far worse, a theological one. It is not a concern of scientists, who will quickly change the subject, if you let them.

If you insist on pursuing the matter they will say that, far from being an exercise in truth-gathering, science is a search for tentative, partial, possible aids and abetments in the eternally ongoing quest for knowledge. It is a search for prosthetic devices to assist the brain in its unsure groping toward external realities, to be discarded as soon as better temporary aids come to hand. The literary or romantic among them will explain patiently that science is a relentless Becoming, never final, never complete, a traveling hopefully, never an arrival. And so on, depending on the extent and intensity of their protests.

They protest too much, too insistently. They are too afraid of appearing immodest, and one can see why. Science is already chastised as a new religion and scientists as its high priests by a wide range of critics, from followers of Thomas Kuhn to deconstructivists. For science has become too successful. To remedy this situation, its detractors the sociologists, philosophers, and historians of science - those who know everything about science, except what it is - turn to spite and postmodernism. Scientists hunker down to escape the flak and, crouching low, disclaim that their work has any connection with truth.

There is an understandable moral cowardice in this, but it is unjustified and, at heart, inexcusable.

Of course science is a creation by humankind, and we are fallible. Of course science is a cultural artifact reflecting its time and place. How could it be otherwise? We do not need the relativists to tell us this.

But, though science does not seek The Truth, it does indeed seek truths, and the truths of science are unlike social truths and unlike moral truths. Within human societies there is always great need for pluralism and tolerance. Science, however, is not a social or a moral truth, it is not a way of bringing disparate ideas together, harmoniously, peacefully, democratically. Science is not pluralistic, nor is it tolerant.

In science, pluralism and tolerance will imperceptibly fade into relativism, where there is no such thing as external truth, objective facts, intrinsic, self-sustaining reality, where there is only "my truth" and "your truth." There is never any need to compare, contrast, question, doubt, argue, seek to learn from what the data say and what the Universe tells us. When this happens, truth - for there is such a thing - is in dire peril. And science ceases to function.

This is the opposite extreme from the fanatic, the person who is certain he is in possession of The Truth. Each extreme, that of the fanatic and that of the relativist, is deadly, for it can tear civilization apart, the one where There Is No Truth, the other where not only is there Truth but I Am in Possession of It, and therefore You had better watch out!

What is truth? said jesting Pilate, not staying for an answer. The linguistic philosopher Alfred Tarski replied that "it is all that is the case," it is "analogous to the function of true in ordinary language." (In other words, truth is what happens to be true.) This, we are informed, is a "semantical theory of truth." I begin to suspect that Gell-Mann's doctor is a wise man.

Perhaps we can do better. Perhaps we can say truth is what is out there, whether we know it to be there or not. We have nothing to do with its creation, but if we are diligent and careful, and perhaps lucky, we can discover truth, bits and pieces of it. Other philosophers believe truth is to be found if we sit very still and think very deeply about it.

Sitting still and thinking is not in and of itself a bad thing, it is what the philosophers like to call "necessary but insufficient," for there is also the pressing need to go out and look, to experiment, observe, collect and make some sense out of the information with which we are in some danger of being drowned, once we open the floodgates of empiricism.

The empirical approach is, as we all know, the scientific approach, and there is nothing particularly new or thrilling about it. It was put forward as a system by David Hume 250 years ago, and even he harbored dark doubts about it. It tells us that what was true about external phenomena is likely to remain true - likely but not certain. This is because external phenomena obey deeper truths, truths we may not know of. Hume went on to argue, in a troubled frame of mind, that just because the sun had risen every morning for countless eons, that is no guarantee that a morning will not come some day when it does not rise. We even know, as Hume did not, that such a morning will indeed come some day, though not for a few billion years yet. This very knowledge of Earth's doom, sad though it may be (for one half of it will inevitably fry as surely as the other half inescapably freezes), is what gives the lie to both fanatic and relativist.