Review of The Domain of Natural Science by E.W. Hobson
Professor Hobson's chair in the University of Cambridge, England, is that of pure mathematics, and he brings to the consideration of the domain of natural science the frame of mind of the mathematician rather than that of the experimental scientist. Mathematics, as an independent discipline, is a science that advances by discovery, but its discoveries seem to lie in a conceptual world rather than in the perceptual world of the experimental scientist. Though physical and statistical sciences find in mathematics an indispensable apparatus in the structure of their hypotheses and later theories, this apparatus does not appear to be fashioned in the same workshop of the scientific imagination, in which are built up the hypotheses of the physical, biological and social sciences. The mathematical apparatus appears to be there at hand, and it consists of abstractions from just those perceptual characters with which these sciences are occupied.
It is therefore natural that a mathematician, who is surveying the field of the natural sciences, should assimilate the theories of those sciences to the conceptual world in which he is operating. Thus Professor Hobson defines a scientific theory as a "conceptual scheme, designed by the synthetic activity of the mind, working with the data of perception, for the purpose of representing particular classes of sequences and regularities in our percepts" (p. 36). He emphasizes the legitimate use of these theories of concepts which have "no direct perceptual counterparts, or it is not assumed a priori that they have such; they are formed by an effort of constructive imagination, for the purpose of
(325) the representative scheme" (p. 32). Again "A law of nature is in reality a conceptual law set up by the activity of the mind of man, but conditional as regards its validity by the perceptual world which must be taken as a datum" (p. 26). Thus a scientific theory does not enable us to know natural objects and their processes as they are there in perception, but gives to us a formula whose abstract symbols so represent and resume perceptual events and things that we can abstract the relations and uniformities that these formulae express, and predicate them of natural phenomena as long as the theories prove valid, and so anticipate the future. Professor Hobson calls this the methodological phenomenalism of science. It leaves science quite free to select its terms or symbols or conceptual objects, and does not commit it in any way to the affirmation of the existence of objects answering to these concepts. Such concepts would be atoms, electrons, laws of nature, any things or events or relations of events which necessarily cannot be brought within perceptual experience. This explains for example the space which is given to Weissmann's theory of heredity, with its idants, its ids, and its biophors, while the author gives but scant and inadequate treatment to Mendelianism. The logical comprehensiveness of Weissmann's theory commends itself to Professor Hobson, while he seems to have little sympathy with the concrete building up of imaginatively perceptual hypotheses, by which the biologist feels his way into the mechanism of heredity, in the use of Mendel's observations and those of others who followed him. Professor Hobson's account of scientific theory belongs to the stage at which the theory has reached a certain finality and may be regarded from the standpoint of its structure and coherence, not to the stage at which it is being worked out in actual research.
It is evident that such a science can offer no evidence as to the existence of anything that lies beyond the range of perception, nor extend its generalizations beyond possible application of its theories. There can then be no conflict between such a science and a religious doctrine or a philosophy that does undertake to go beyond the range of perception, provided these do not interfere with the freedom of science to formulate its own theories and test their applicability to the perceptual world. "Any such general Philosophy must provide within itself a place which Natural Science may occupy as an autonomous system" (p. 470). "Subject to completely adequate satisfaction of this condition, natural science offers no obstacle to the free development of theistic or other philosophies on their own lines, in the sense that no other purely logical consequences follow from the acceptance of natural science, which are effective in the wider domains of thought" (p. 470). However,
(326) it will be seen at once that in the field within which most of the conflicts of science and religion do take place -- e.g. that of evolution and that of miracles -- the freedom to formulate and apply scientific theories has not quieted the quarrel. As over against a scientific determinism and exclusion of teleology from the world, Professor Hobson's dictum would remove any scientific justification for denying moral responsibility or the existence of a divine plan in the world, provided proof for these is not sought in events which could be scientifically otherwise explained. When we recognize that scientific method is nothing but the rigorous and detailed development of our everyday intelligence, it will be seen that the limitations of its phenomenalistic method must apply to all inferences, except those based upon a faith or a metaphysics that is hopelessly divorced from intelligible findings of daily life. Professor Hobson is very emphatic in restricting the phenomenalism of science to method. He does not realize that this brings all of our intelligent interpretation of the world within the same phenomenalism, and that in doing this he has left unaffected the quarrel between science and religion except in so far as this is a quarrel between two metaphysical systems. Although abjuring philosophy, in formulating scientific method as he does forbid the scientist to be a realist, and dissociates himself sharply from a profound mathematical philosopher, Professor A. N. Whitehead, who is a realist and who insists that a scientific concept must be a concept of something, that it cannot be a mere symbol for something that cannot be conceived.
In psychology Professor Hobson follows Ward. He denies any scientific justification to a parallelism which would exclude psychical efficiency. This denial is based upon the inability of science to give a complete mechanistic account of human conduct, and the extreme improbability of it ever doing this. He argues that interaction does not contravene the first thermo-dynamic law -- that of the conversion of energy -- but only the second -- that of entropy -- for whose generalization, in the theory of energy, he finds no justification. However, Professor Hobson denies that psychology and the social sciences which are applications of psychology can be natural sciences, for he recognizes that in that way lies a mechanical parallelism if his phenomenalistic method of science is adopted. It is interesting to see that having excluded the perceptual world from the content of knowledge of the natural sciences, he is obliged to take psychology and the social sciences out of its number also, except in so far as their method is purely statistical. This is interesting because human intelligence is turning with more and more confidence to the application of scientific method to its social problems. It cer-
(327)-tainly raises a question as to the adequacy of Professor Hobson's account of scientific method.
Between the formulation, in this volume, of the theory of scientific method, and the final chapters on the relation of natural science and philosophy and theology, lie chapters on the fields and history of the physical and biological sciences. I have already indicated what appears to me the shortcoming of the account of heredity. Apart from this these accounts are extraordinarily well done. The chapter on "Relativity" is not only masterly in its presentation of the Einsteinian doctrine but remarkably clear and comprehensible. The same may be said for his account of arithmetic and geometry. One may not agree with his conceptual theory in these fields, but no one can deny his competence and clarity in presenting the most abstruse ideas. The book is a notable one in the field of the philosophy of science, and none the less important because his doctrine of scientific method is open to so much more question that Professor Hobson seems to realize.
George H. Mead
University of Chicago