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"Thus, my friends," said Barbicane, "all motion suddenly stopped produces heat. And this theory allows us to infer that the heat of the solar disc is fed by a hail of meteors falling incessantly on its surface. They have even calculated - " "Oh, dear !" murmured Michel, "the figures are coming."
On the theory of natural selection we can clearly understand the full meaning of that old canon in natural history, 'Natura non facit saltum.' This canon, if we look only to the present inhabitants of the world, is not strictly correct, but if we include all those of past times, it must by my theory be strictly true.
First you must have faith in an eternal world independent of you; then you must have faith in your ability to perceive it, and finally you must try to explain it by means of concepts or mathematical constructions. But don't always accept traditional concepts without reexamining them. Even overthrow my relativity theory, if you find a better one.... You must believe that the world was created as a unified whole which is comprehensible to man. Of course, it's going to take an infinitely long time to investigate this unified creation. But to me that is the highest and most sacred duty—unifying physics. Simplicity is the criterion of the universe.
When we descend to details, we can prove that no one species has changed (i.e., we cannot prove that a single species has changed): nor can we prove that the supposed changes are beneficial, which is the groundwork of the theory. Nor can we explain why some species have changed and others have not.
A priori one should expect a chaotic world which cannot be grasped by the mind in any way... The kind of order created by Newton's theory of gravitation...is wholly different. Even if the axioms of the theory are proposed by man, the success of such a project presupposes a high degree of ordering of the objective world.... That is the "miracle" which is being constantly reinforced as our knowledge expands.
It is essential to grasp the incontestable truth that a Marxist must take cognisance of real life, of the true facts of reality, and not cling to a theory of yesterday, which, like all theories, at best only outlines the main and the general, only comes near to embracing life in all its complexity.
How it happened that I in particular discovered the relativity theory, it seemed to lie in the following circumstance. The normal adult never bothers his head about space-time problems. Everything there is to be thought about it, in his opinion, has already been done in early childhood. I, on the contrary, developed so slowly that I only began to wonder about space and time when I was already grown up. In consequence I probed deeper into the problem than an ordinary child would have done.
Although I'm regarded as a dangerous radical by particle physicists for proposing that there may be loss of quantum coherence, I'm definitely a conservative compared to Roger. I take the positivist viewpoint that a physical theory is just a mathematical model and that it is meaningless to ask whether it corresponds to reality. All that one can ask is that its predictions should be in agreement with observation. I think Roger [Penrose] is a Platonist at heart but he must answer for himself.