GERALD HOLTON
Mallinckrodt Research Professor of Physics and Research Professor of History of Science, Harvard University; Author, Thematic Origins of Scientific Thought

The Increasing Coalescence of Scientific Disciplines

Under our very eyes, research in science has been taking a courageous and promising turn, to realize in our time an ancient dream.

Since Thales and other philosophers on the island in the Ionian Sea, over 2500 years ago, there has been an undying hope that under all the diverse and fluctuating phenomena, there could be found in Nature a grand, majestic order. This fascination, the "Ionian Enchantment," persisted ever since in various forms.

Thus, Isaac Newton thought mechanical forces that explained the motions of the solar system would also turn out to run all else, including human senses. After Darwin's magnificent synthesis, many attempts were made to extend it to include all societal phenomena. The influential Austrian polymath, Ernst Mach, to whom young Einstein referred as one of his most important influences, taught that the true task of scientific research is to establish a form of fundamental science, an Einheitswissenschaft, on which is based every different specialty. From about 1910 on, an increasing number of scientists in Europe and America gave allegiance to the idea of the "Unity of Science," a widespread movement hoping to find functioning bridges between not only different sciences but also between science and philosophy—Niels Bohr being one of the prominent promoters.

But, by and by, it became clear that such hopes were at best premature, that there was not enough of what William James had called "cash value," in terms of having secured many actual accomplishments—not least in attaining a Unified Field Theory. At one of the last meetings devoted to discussions about the Unity of Science, in 1956, J. Robert Oppenheimer, with typical eloquence, offered a valedictory to the Ionian Enchantment, with these words:

"It may be a question [whether there] is one way of bringing a wider unity in our time. That unity, I think, can only be based on a rather different kind of structure than the one most of us have in mind....The unity we can seek lies really in two things. One is that the knowledge that comes to us in such terrifyingly inhumanly rapid rate has some order in it....The second is simply this: We can have each other to dinner. We ourselves, and with each other by our converse, can create, not an architecture of global scope,but an immense, intricate network of intimacy, illumination, and understanding."

But even as such opinions were accepted with resignation, something new had been born, quietly grew, and in our time has become the source of increasing optimism about the value of the old dream—by turning in a new direction. I mean that scientific research, at first only sporadically during the last century, but more and more in our time, has been successfully reaching out for a new sort of unity—in practice, for an integration among disciplinary fragments. This time the movement is not driven by a philosophy of science or a search for the Ur-science. Rather it is appearing as if spontaneously in the pursuit and progress of research science itself.

There is an increasing coalescence of scientific disciplines in many areas. Thus the discovery of the structure of the genome not only required contributions from parts of biology, physics, chemistry, mathematics, and information technology, but in turn it led to further advances in biology, physics, chemistry, technology, medicine, ecology, and even ethics. And all this scientific advance is leading, as it should, to the hopeful betterment of the human condition (as had been also one of the platform promises of the Unity of Science movement, especially in its branch in the Vienna Circle).

Similar developments happen in the physical sciences—a coalescence of particle physics and large-scale astronomy, of physics and biology, and so forth. It is a telling and not merely parochial indicator that about half of my 45 colleagues in my Physics Department, owning to their widespread research interests, now have joint appointments with other departments at the University: with Molecular and Cellular Biology, with Mathematics, with Chemistry, with Applied Sciences and Engineering, with History of Science. Just now, a new building is being erected next to our Physics Department. It has the acronym LISE, which stands for the remarkable name, Laboratory of Integrated Science and Engineering. Although in industry, here and there, equivalent labs have existed for years, the most fervent follower of the Unity of Science movement would not have hoped then for such an indicator of the promise of interdisciplinarity. But as the new saying goes, most of the easy problems have been solved, and the hard ones need to be tackled by a consortium of different competences.

From other parts of this university, plans are under way to set up a program for higher degrees in the new field of Systems Biology, which has the goal of reaching "an integrated understanding" of biological/medical processes; that program is to bring together faculty and students from biology, medicine, chemistry, physics, mathematics, computation and engineering. And these parochial examples are indications of a general trend in many universities. The new password to success is now "integration" and "interdisciplinarity." If an "official" sacralization of this movement were needed, it would be the 2005 release of a big volume by the National Academy of Sciences, with the title "Facilitating Interdisciplinary Research."

All this is not precisely what the philosophers and scientists, from Thales on, were hoping for. We will not, at least not for a long time, have that grand coalescence of all sciences and more. What has come lacks exalted philosophical pretensions, being instead a turn to weeks and years of many-heads-together, hands-on work on specific, hard problems of intense scientific interest, many of them also of value to society at large.

And, of course, these co-workers can also still have each other to dinner.

DONALD HOFFMAN
Cognitive Scientist, UC, Irvine; Author, Visual Intelligence

We Will Soon Devise a Scientific Theory for the Perennial Mind-Body Problem

The enigmatic relation between conscious experiences and the physical world, commonly known as the mind-body problem, has frustrated philosophers at least since Plato, and now stonewalls scientists in their attempts to construct a rigorous theory. Yet I am optimistic that, despite millennia of prior failures, we will soon devise a scientific theory for this perennial problem.

Why such optimism? First, the mind-body problem is now recognized as a legitimate scientific problem. In 2005, the journal Science placed it second in a list of 125 open questions in science. During the twentieth century, a multi-decade detour into behaviorism sidelined scientific investigation of the mind-body problem. But three decades into the cognitive revolution, the problem was dusted off and again given serious scientific attention.

Second, scientists soon rediscovered that the problem is surprisingly hard. Neurophysics, real and artificial neural networks, classical and quantum algorithms, information and complexity—standard tools that prove powerful in the study of perception, cognition and intelligence—have yet to yield a single scientific theory of conscious experiences. We cannot, for instance, answer the basic question: Why must this particular pattern of neural activity or this functional property cause, or be, this particular conscious experience (say, the smell of garlic) instead of that other conscious experience (say, the smell of a truffle), or instead of no conscious experience at all? Precise predictions of this type, de rigueur for genuine scientific explanations, have yet to be fashioned, or even plausibly sketched, with the standard tools.

Third, although science is laudably conservative, yet when pushed to the wall by recalcitrant data and impotent theories, scientists have repeatedly proved willing to reexamine dearly held presuppositions and to revise or jettison the ineffectual in favor of unorthodox assumptions, provided that these assumptions permit the construction of explanatory theories that answer to data. Aristarchus, then Copernicus, countenanced a heliocentric solar system, Newton action at a distance, Einstein quanta of light and distortions of space-time, Bohr probability waves, superpositions and nonlocality. Theories of quantum gravity now posit eleven dimensions, vibrating membranes, and pixels of space and time. The initial response to such proposals is, invariably, widespread incredulity. But considerations of explanatory power and empirical adequacy, wherever they point, eventually win the day. Scientists revise their offending presuppositions, adjust psychologically as best they can to the new world view, and get on with the business of science in the new framework.

Evidence is mounting that the mind-body problem requires revision of deeply held presuppositions. The most compelling evidence to date is the large and growing set of proposals now on offer. All are nonstarters. They are, to quote Pauli, not even wrong. We have yet to see our first genuine scientific theory of the mind-body problem. This has prompted some to conclude that homo sapiens has been cheated by evolution and simply lacks the requisite concepts: Those concepts necessary for us to survive long enough to reproduce did not include those necessary to solve the mind-body problem. If so, there is little hope, at present, for swift progress.

I am optimistic, however, that the obstacle is not in our genes but in our presuppositions. Tinkering with presuppositions is more clearly within the purview of current technology than tinkering with our genes. Indeed, tinkering with one's presuppositions requires no technology, just a ruthless reconsideration of what one considers to be obviously true. Science has risen to the task before. It will rise again. But progress will be tortuous and the process psychologically wrenching. It is not easy, even in the light of compelling data and theories, to let go of what once seemed obviously true.

Here are some obvious truths that guide current attempts to solve the mind-body problem: Physical objects have causal powers. Neural activity can cause conscious experiences. The brain exists whether or not it is observed. So too does the moon, and all other physical objects. Consciousness is a relative latecomer in the evolution of the universe. Conscious sensory experiences resemble, or approximate, true properties of an independently existing physical world.

Will we soon be forced to relinquish some of these truths? Probably. If so, the current ontological predilections of science will require dramatic revision. Could science survive? Of course. The fundamental commitments of science are methodological, not ontological. What is essential is the process of constructing rigorous explanatory theories, testing them with careful experiments, and revising them in light of new data. Ontologies can come and go. One might endure sufficiently long that it is taken for a sine qua non of science. But it is not. An ontology breathed into life by the method of science can later be slain by that same method. Therein lies the novel power of science. And therein lies my optimism that science will soon succeed in fashioning its first theory of the mind-body problem. But at the feet of that theory will probably lie the slain carcass of an effete ontology.

ANDREW BROWN
Journalist, The Guardian; Author, The Darwin Wars

A Proper Scientific Understanding of Irrationality In General, and of Religion In Particular

I'm not actually optimistic about anything very much, but it's clear that if civilisation is to survive, we need a proper scientific understanding of irrationality in general, and of religion in particular. To be optimistic about that is a precondition for optimism about anything else. What might such an understanding look like?

For a start, it would be naturalistic and empirical. It would not start from definitions of religion or faith, but from a careful study, in the spirit of William James, of how it is that religious people actually behave and believe. What would be found, again in a Jamesian spirit, is that there are varieties of religious behaviour, as there are varieties of religious experience. We would need to know how these are related to each other, and to other things that are not described as religious. It may well be that "religion" is a concept no more useful than phlogiston.

It would take seriously Dan Dennett's distinction between beliefs and opinions—more seriously, I think, than he sometimes does himself. A belief, in Dennett's sense, is a kind of behaviour or a propensity to behave as if certain things were true. It need not be conscious at all. The kind of conscious, articulable propositions about the world which most people mean by "belief" he calls an "opinion".

In this sense, an enquiry into religious belief would be distinct from an enquiry into religious opinions: Religious "belief" would involve all of the largely unconscious mechanisms which lead people to behave superstitiously, or reverently, or with a disdain for heretics; religious opinions would be the reasons that they give for this behaviour. We need to understand both. It may be that their opinions would correspond to their beliefs but that is something to be established in every case by empirical enquiry. It's obvious that in most cases they don't. Intellectuals are supposed to be motivated by their opinions; some of them actually are. But everyone is motivated by their beliefs and prejudices as well.

In particular, such an enquiry would be very careful about what counts as evidence. A friend of mine who does consciousness research once said sourly that "The problem with the brain is that if you go looking for something in there, you're very liable to find it." Similarly, if you go looking for some particular quality in religious belief you are likely to find it there, as well as its opposite. What's needed is the distinctly scientific attitude that takes disconfirming evidence seriously, and doesn't respond to it by simply repeating the confirming evidence.

I happened to see a play "On Religion" by the British atheist philosopher AC Grayling last night, which is an excellent dramatisation of some of these issues. The atheist character, a woman lecturer, is given a speech in which she recounts the story of a scientist who has spent fifteen years arguing that the Golgi apparatus does not in fact exist. It is an artifact of the inadequacies of our microscopes. Finally, he attends a lecture from a visiting cell biologists who proves conclusively that the Golgi apparatus does exist. And, just as the whole department is trying to avoid his eye from sympathetic shame, he rushes up to the lecturer, grabs his hand, and says "My dear fellow, I wish to thank you. I have been wrong these fifteen years." It is an improving and inspiring story, which pitches over into bathos as soon as the atheist spells out the moral. "No religious person could ever say that" she says. Has she really never heard of the phenomenon of conversion? What do the converted say, if not that some evidence has convinced them they were wrong all their lives before?

So, I think, if I am to be optimistic, that there will be a real breakthrough in the empirical study of religion, at the end of which no scientist will ever feel able to assert that "no religious person could ever say" without making a careful enquiry into what religious people actually do say and what they mean by it.