WHAT IS TO BE understood by Science? It means, first, a general Method, or Logic of Search, applicable to all departments of knowledge; and secondly, a Doctrine, or body of truths and hypotheses, embracing the results of search. In this second acceptation there are the particular sciences—such as Mathematics, Physics, Chemistry, Biology, Psychology, &c.—which are the special applications of the general Method to special departments of knowledge; and although there is an interdependence of these sciences, each is restricted to its own class of facts, none can legislate for the others. But because the various branches of knowledge have been very unequally reduced to the exactness and orderliness of Science, those which have been most successfully reduced have acquired the almost exclusive title; so that Science is generally regarded as something apart—the peculiar study of a particular class. Hence also the opinion that there is a profound separation between the principles applicable in the Physical Sciences and the principles applicable in the Moral Sciences. What has been the consequence? It has been that the Method which is no longer regarded as a rational procedure in dealing with the phenomena of Human Nature; and the supernaturalism long banished from physical theories is still invoked in psychological and social theories.

Of late years this has ceased to be the universal error, though it still remains a widespread error. We are slowly beginning to recognise that there may be a science of History, a science of Language, a science of Religion, and, in fact, that all knowledge may be systematised on a common Method. The facts of the External Order, which yield a Cosmology, are supplemented by the facts of the Internal Order, which yield a Psychology, and the facts of the Social Order, which yield a Sociology. These are all comprised in Science. However imperfect the second and third may be, in comparison with the first, the greater complication of the phenomena does not warrant the introduction of another Logic of Search. The principles which have guided us successfully in the first are to be followed in the others. The three classes of facts are all facts of Experience, so far as they are known, and must all be tested, classified, and systematised by the same rules.

This being so, we can separate the rational from the irrational antagonism against Science. It is rational when protesting against the misplaced application of the results reached in one department to problems belonging to a different department—for this is an offence against scientific Method. It is irrational when protesting against the rigorous application of one Logic to all inquiries. Those, therefore, who sneer at Science, and would obstruct its diffusion, are sneering against the effort to make all Knowledge systematic, and are obstructing the advance of civilisation.

The notion, implied or expressed, of two Logics, two Methods of Search, two systems of explaining phenomena, the natural and the supernatural, is the foundation of the great conflict between Science and Theology. And since in the majority of minds, Theology is identified with Religion, and Religion is of supreme importance to man, it is natural that Science should be regarded with dread and dislike. Before proceeding to dissipate the confusions on this subject, it will be needful to glance at the attitude of sincere theologians in our day, and at the reasons which justify to their minds the acceptance of scientific doctrines side by side with the acceptance of theological doctrines. It would be equally ungenerous and short-sighted to suggest that a mind which is deeply impressed with the truth of certain theological opinions may not be also deeply impressed with the beneficence of Science in general, and the truth of scientific doctrines which do not directly embrace moral and religious questions. We have too many conspicuous examples of men eminent in Science and sincere in their theological professions, not to admit that the mind can follow two Logics, and can accept both the natural and the supernatural explanations. Whether the mind ought to do so, is another question. Let no one therefore suspect me of a doubt as to the sincerity of theologians who proclaim that the sphere of Science is limited to the processes of the physical world, and may be frankly accepted in all that it teaches respecting such processes, without in the least involving the moral world which Theology derives from a source independent of experience. Science, they say, systematises whatever experience reveals; its test is Reason. Theology systematises what had been revealed from a higher source; its test is Faith. Between Reason and Faith there is an absolute demarcation; and between Science, which relies on observation and induction, and Theology, which relies on precept and intuition, there is no conflict. As the artist appeals to the chemist for a theory of salts, and to the mathematician for a theory of singular integrals, but declares both chemist and mathematician to have no voice in a theory of Art, so the theologian accepts the teaching of mathematician, physicist, chemist, and biologist, in their respective departments, but peremptorily excludes each and all from the supreme department of moral and religious duties founded on a theory of the relations of the world to its creator.