The Physicist as Philosopher

Essays 1958-1962 on Atomic Physics and Human Knowledge

by Niels Bohr
Interscience Publishers, 100 pp., $5.00

My View of the World

by Erwin Schrödinger
Cambridge, 120 pp., $3.50

The Relevance of Science

by C.F. von Weizsäcker
Harper & Row, 192 pp., $5.00

One of the minor crosses that Albert Einstein bore through the last thirty years of his life was the way in which people of all kinds and backgrounds turned to him for pronouncements: pronouncements about democracy and liberty, about aesthetics and free love—above all, about philosophy. Just because of the intellectual penetration shown in his analysis of our spatial and temporal concepts, they hoped for a further revelation; and indeed, the term “relativity” became for a while a catch-phrase far beyond the widest-drawn boundaries of mathematical physics. On his own side, Einstein himself was fully aware of the limitations of his experience, and felt keenly embarrassed when his personal opinions were treated with inappropriate deference. Some people may be tempted to comment, “And quite right, too!” Yet there is a little more to the matter than this. Throughout intellectual history there has been a continuous interaction at the theoretical level between the ideas of physics and those of philosophy—between physics (one might say) and the rest of philosophy, since today’s physical theory is the lineal descendant of yesterday’s “natural philosophy.” Certain genuinely philosophical problems—e.g., those at issue between Leibniz and Clarke—lose most of their force and point for twentieth-century readers if divorced from scientific considerations; and over such issues the contributions of a Poincaré or an Einstein may in fact help directly to clear our philosophical minds. The patterns of interaction between physics and philosophy are, however, not fixed timelessly: they change from generation to generation. The specific relevance of new modes of thought in physical theory to (say) epistemology or philosophical theology is something which has continually to be explored afresh. So the philosophical views of physicists of such intellectual distinction as Niels Bohr or Erwin Schrödinger must be of interest both for biographical reasons and more generally.

Since the time of Tycho Brahe, Denmark has surely had no more profound scientific thinker than Niels Bohr. By the time of his death, he was probably the most widely respected, and certainly the most widely loved man in his profession. Like his teacher Ernest Rutherford, he was a natural leader: his home at Copenhagen was the center of a series of concentric intellectual circles, which expanded outwards to embrace the whole world-community of theoretical physicists. In a century of growing scientific nationalism, too, he was the last of the instinctive scientific internationalists: his abortive wartime interview with Churchill (described in Mrs. Gowing’s recent history of the British atomic energy program) had an irony worthy of Berthold Brecht. Scientifically, Bohr made an enduring mark as the Pythagoras of atomic structure—as the man who saw how, from the sharply-defined wavelengths in the line-spectra of electrically-excited gases, one might decipher the internal arrangement of the electrons in the gas-atoms. (This was the discovery which led Einstein to exclaim, echoing Kepler, “Hier ist höchste Musikalität im Raüme des Gedenkens.”)

Philosophically, Bohr’s mind became occupied more and more with the idea of “complementarity,” which he endeavored to expand from its starting-point in physics to resolve…

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