Recently, as a result of my most recent book, A Universe from Nothing, I participated in a wide-ranging and in-depth interview for The Atlantic on questions ranging from the nature of nothing to the best way to encourage people to learn about the fascinating new results in cosmology. The interview was based on the transcript of a recorded conversation and was hard hitting (and, from my point of view, the interviewer was impressive in his depth), but my friend Dan Dennett recently wrote to me to say that it has been interpreted (probably because it included some verbal off-the-cuff remarks, rather than carefully crafted written responses) by a number of his colleagues and readers as implying a blanket condemnation of philosophy as a discipline, something I had not intended.
Out of respect for Dan and those whom I may have unjustly offended, and because the relationship between physics and philosophy seems to be an area which has drawn some attention of late, I thought I would take the opportunity to write down, as coherently as possible, my own views on several of these issues, as a physicist and cosmologist. As I should also make clear (and as numerous individuals have not hesitated to comment upon already), I am not a philosopher, nor do I claim to be an expert on philosophy. Because of a lifetime of activity in the field of theoretical physics, ranging from particle physics to general relativity to astrophysics, I do claim however to have some expertise in the impact of philosophy on my own field. In any case, the level of my knowledge, and ignorance, will undoubtedly become clearer in what follows.
As both a general reader and as someone who is interested in ideas and culture, I have great respect for and have learned a great deal from a number of individuals who currently classify themselves as philosophers. Of course as a young person I read the classical philosophers, ranging from Plato to Descartes, but as an adult I have gained insights into the implications of brain functioning and developments in evolutionary psychology for understanding human behavior from colleagues such as Dan Dennett and Pat Churchland. I have been forced to re-examine my own attitudes towards various ethical issues, from the treatment of animals to euthanasia, by the cogent and thoughtful writing of Peter Singer. And reading the work of my friend A.C. Grayling has immeasurably heightened my understanding and appreciation of the human experience.
What I find common and so stimulating about the philosophical efforts of these intellectual colleagues is the way they thoughtfully reflect on human knowledge, amassed from empirical explorations in areas ranging from science to history, to clarify issues that are relevant to making decisions about how to function more effectively and happily as an individual, and as a member of a society.
As a practicing physicist however, the situation is somewhat different. There, I, and most of the colleagues with whom I have discussed this matter, have found that philosophical speculations about physics and the nature of science are not particularly useful, and have had little or no impact upon progress in my field. Even in several areas associated with what one can rightfully call the philosophy of science I have found the reflections of physicists to be more useful. For example, on the nature of science and the scientific method, I have found the insights offered by scientists who have chosen to write concretely about their experience and reflections, from Jacob Bronowski, to Richard Feynman, to Francis Crick, to Werner Heisenberg, Albert Einstein, and Sir James Jeans, to have provided me with a better practical guide than the work of even the most significant philosophical writers of whom I am aware, such as Karl Popper and Thomas Kuhn. I admit that this could primarily reflect of my own philosophical limitations, but I suspect this experience is more common than not among my scientific colleagues.