Another scientist, who accepts Idealism as a scientific philosophy is Sir James Jeans. This renowned British Physicist has expressed his philosophical views in his famous work-77ze Mysterious Universe. Like Eddington, he also does not deny the existence of objective reality. But he believes that human knowledge (this includes also the scientific knowledge) is confined only to the subjective reality-that "the real essence of substances is for ever unknowable." In his own words, we find-"When we try to discover the nature of the reality behind the shadows, we are confronted with the fact that all discussions of the ultimate nature of things must necessarily be barren unless we have some extraneous standards against which to compare them. For this reason, to borrow Locke's phrase, "the real essence of substances" is for ever unknowable. We can only progress by discussing the laws which govern the changes of substances, and so produce the phenomena of the external world. These we can compare with the abstract creations of our mind."[1]
According to Jeans, the human knowledge in the forms of Science and Mathematics concerns only to the behaviour of the substances and not the substances themselves. Thus the universe described by the symbol and formulae of Science and Mathematics is only the creation of our mind. He tells us, "A mathematical formula can never tell us what a thing is, but only how it behaves; it can only specify an object through its properties. And these are unlikely to coincide in toto with the properties of any single microscopic object of our everyday life."[2]
Jeans was conscious of the fact that this would mean giving up of Realism, which he did not desire. Therefore, he tried to clarify it thus, "This may suggest that we are proposing to discard Realism entirely, and enthrone a thorough-going Idealism in its place. Yet this, I think, would be too crude a statement of the situation. If it is true that the 'real essence of substances' is beyond our knowledge, then the line of demarcation between realism and idealism becomes very blurred indeed; it becomes little more than a relic of a past age in which reality was believed to be identical with mechanism. Objective realities exist, because certain things affect your consciousness and mine in the same way, but we are assuming something we have no right to assume if we label them as either 'real' or 'ideal'. The true lable is, I think, 'mathematical,' if we can agree that this is to connote the whole of pure thought and not merely the studies of the professional mathematician. Such a label does not imply anything as to what things are in their ultimate essence, but merely something as to how they behave."[3] In this way, Sir James Jeans considers the universe to consist of pure thoughts. But, still he describes it to be 'substantial'. He writes, "The label we have selected does not of course relegate matter into the category of hallucination or dreams. The material universe remains as substantial as ever it was, and this statement must, I think, remain true through all changes of scientific or philosophical thought."[4] Further explaining the concept of 'substantiality' he says, "Substantiality is a purely mental concept measuring the direct effect of objects on our sense of touch. We say that a stone or a motor car is substantial, while an echo or a rainbow is not. This is the ordinary definition of the word, and it is a mere absurdity, a contradiction in terms, to say that stones and motor cars can in any way become insubstantial, or even less substantial, because we now associate them with mathematical formulae and thoughts, or kinks in empty space, rather than with crowds of hard particles."[5]
The most important aspect of Jeans' s philosophical thoughts is that he considers 'mind' as the objective reality and the physical universe as a creation of this 'mind'. Emphasising this point, he states, "The old dualism of mind and matter, which was mainly responsible for the supposed hostility seems likely to disappear, not through matter becoming in any way more shadowy or insubstantial than heretofore, or through mind becoming resolved into a function of the working of matter, but through substantial matter resolving itself into a creation and manifestation of mind."[6] Finally, in Jeans' s philosophy, we also get an indication of his belief in the Supreme Reality, whom he considers as a Mathematician, the universe being the creation of this Mathematician. This view is expressed thus: "If all this is so, then the universe can be best pictured, although still very imperfectly and inadequately, as consisting of pure thought, the thought of what, for want of a wider word, we must describe as a mathematical thinker."[7] More clearly he remarks. "From the intrinsic evidence of His creation, the Great Architect of the Universe now begins to appear as a pure mathematician."[8]
Concluding the discussion of Jeans' s philosophy, we can say that he advocates idealism on the basis of modern scientific thoughts.