I think it will be agreed that there is a domain of investigation where physics and philosophy overlap. There are branches of philosophy which do not approach the subject-matter of physics, and a great part of the work of practical and theoretical physicists is not aimed at extending our knowledge of the fundamental nature of things; but questions which concern the general interpretation of the physical universe and the significance of physical law are claimed by both parties. I suppose that ideally the physicist should be allowed to elucidate his own universe up to a point, and then hand it over to the philosopher to ascertain its exact status in relation to a wider outlook.