TWO SCHOOLS OF THOUGHT IN THE REVOLUTION IN PHYSICS AT THE T(5)

Poincare was also acutely aware of the crisis in physics. In The Value of Science, published in 1905, he wrote, “I believe that there are indications of a serious crisis” pointing to an “approaching transformation”21 in physics. Poincare thought that the crisis in physics marks “the eve of revolution,” and the forewarning that physics is entering “an even more important stage.”22 Therefore, “be not too anxious. We are sure the patient will not ” die of it, and we may even hope that this crisis will be salutary.23 poincare was optimistic about the future of science. He noted that we already have “the cathode rays, the x-rays, those of uranium and of radium. Herein is a whole world which no one suspected. How many unexpected guests must be stowed away!”24 He firmly concluded, “if the past has given us much, we may rest assured that the future will give us still more.”25
Although the physicists of the Critical School criticized classical mechanics and classical physics, they did not completely reject them. In Mechanics, Mach highly praised Newton’s Principia Mathematica. He argued that, from a historical point of view, mechanical principles are easily understood and their faults are excusable. They are both effective and valuable within a limited period of time and in certain areas. In The Grammar of Science Pearson remarked, “All that modern science will do to the dynamics of Newton and Lagrange will be to define precisely within what limits their application is exact, or with what approximation they may be applied if exactness is not to be admitted.”26
Poincare also emphasized many times that the basic principles of classical physics are of “high value; they were obtained in seeking what there was in common in the enunciation of numerous physical laws; they represent therefore, as it were, the quintessence of innumerable observations.”27 Of course, “it would be necessary to keep a place for them. To determine to exclude them altogether would be to deprive oneself of a precious weapon.”28 Speaking of classical physics, he particularly emphasized,
I do not mean it corresponds to no objective reality, nor that it reduces itself to a mere tautology, since, in each particular case, and provided one does not try to push to the absolute, it has perfectly clear meaning…It will disappear only to lose itself in a higher harmony.29
It is particularly worth nothing that Poincare directly criticized the erroneous claim that the crisis in physics is an indication of “the bankruptcy of science.” He wrote,
The laity are struck to see how ephemeral scientific theories are. After some years of prosperity, they see them successively abandoned; they see ruins accumulate upon ruins. They foresee that the theories fashionable today will shortly succumb in their turn and hence they conclude that these are absolutely idle. This is what they call the bankruptcy of science.
Poincare penetrated to the heart of the matter when he noted, “That kind of skepticism is superficial. They absolutely fall to consider the purposes and functions of scientific theories. Otherwise, they would understand that these ruins may be useful.”30 Thus, the accusation that the Critical School entirely denied the old principles of physics and proclaimed the total collapse of scientific truth is not in accordance with the facts.