How do we discover the individual laws of Physics, and what is their nature? It should be remarked, to begin with, that we have no right to assume that any physical law exists, or if they have existed up to now, that they will continue to exist in a similar manner in the future. It is perfectly conceivable that one fine day Nature should cause an unexpected event to occur which would baffle us all; and if this were to happen we would be powerless to make any objection, even if the result would be that, in spite of our endeavors, we should fail to introduce order into the resulting confusion. In such an event, the only course open to science would be to declare itself bankrupt. For this reason, science is compelled to begin by the general assumption that a general rule of law dominates throughout Nature.

My original decision to devote myself to science was a direct result of the discovery which has never ceased to fill me with enthusiasm since my early youth—the comprehension of the far from obvious fact that the laws of human reasoning coincide with the laws governing the sequences of the impressions we receive from the world about us; that, therefore, pure reasoning can enable man to gain an insight into the mechanism of the latter. In this connection, it is of paramount importance that the outside world is something independent from man, something absolute, and the quest for the laws which apply to this absolute appeared to me as the most sublime scientific pursuit in life.

Religion belongs to the realm that is inviolable before the law of causation and therefore closed to science.

The highest court is in the end one’s own conscience and conviction—that goes for you and for Einstein and every other physicist—and before any science there is first of all belief. For me, it is belief in a complete lawfulness in everything that happens.

The quantum hypothesis will eventually find its exact expression in certain equations which will be a more exact formulation of the law of causality.

The worth of a new idea is invariably determined, not by the degree of its intuitiveness—which incidentally, is to a major extent a matter of experience and habit—but by the scope and accuracy of the individual laws to the discovery of which it eventually leads.

This is one of man's oldest riddles. How can the independence of human volition be harmonized with the fact that we are integral parts of a universe which is subject to the rigid order of nature's laws?

We have no right to assume that any physical law exists, or if they have existed up to now, that they will continue to exist in a similar manner in the future.

What led me to my science and what fascinated me from a young age was the, by no means self-evident, fact that our laws of thought agree with the regularities found in the succession of impressions we receive from the external world, that it is thus possible for the human being to gain enlightenment regarding these regularities by means of pure thought