The only charge that might be directed against the scientific attitude (which in this case is also that of the man in the street) is that this objective world resolves itself into a series of inferences, a mere mental construct, hence cannot possess the same measure of reality as the impressions we experience directly. The majority of scientists would grant the justice of this charge if by “what we experience directly” we mean our awareness of sensations. But they would strenuously oppose the claims of the neo-realist who endeavours to extend the meaning of these words so as to embrace the existence of his sensa and sense-objects; these represent nothing but inferences which he has drawn from his awareness of sensations. And this is precisely the error into which the neo-realist falls when, on perceiving a red flash in the sky, he talks of a star bursting into prominence “there-now.” If he wishes to avoid inferences, he should confine himself to saying: “I experience ‘here-now’ a luminous impression on a dark background.” For all he knows, the luminous impression may be due to an aviator’s light, or to a firefly, or to a purely subjective hallucination. [Pg 177] At any rate, the point we wish to stress is that while it is correct to say that the objective world is a synthesis of private views or perceptions, we should not forget to add that the private views are themselves the product of a synthesis of sensations. But inasmuch as science must deal with the general, and not merely with the particular, and inasmuch as it is the common objective world that renders this general knowledge possible, it will be this world that the scientist will identify with the world of reality. Henceforth the private views, though just as real, will be treated as its perspectives. We must recognise, therefore, that the common objective world, whether such a thing exists or is a mere convenient fiction, is indispensable to science, if in no other capacity than as a working hypothesis. And neo-realism, as we have said, when pursued consistently, renders a collective view impossible. Furthermore, from the standpoint of science, whether it be classical physics, relativity, physiology or psychology, neo-realism is untenable, for under no circumstances can vision and our knowledge of nature in general be considered a matter of direct apprehension. In much the same way, we know that 7 times 8 is 56, and we obtain this result immediately, without reflection and without having to count on our fingers. Were it not for the fact that the neo-realist recollects the difficulty he experienced in learning the multiplication table, he would presumably be telling us that our knowledge of the properties of numbers was also a matter of direct recognition. From the standpoint of science, there is very little difference between the alleged immediacy of perception and our knowledge of the product of 7 times 8. Neither of these two forms of