SCIENCE AND THE UNOBSERVABLE — DINGLE 211 



Einstein. The point M. Maritain really wishes to make is that the 

 nature of the thing we observe, whether we measure it or not, is inde- 

 pendent of our devices for observing it and should, therefore, be inde- 

 pendently defined.) 



It is not surprising that a physicist and a philosopher should take 

 opposite views of this question, but the matter cannot be disposed of 

 on simple psychological grounds. Here are the diametrically opposed 

 views of two men of science: 



The general point of view [of relativity, writes Prof. C. G. Darwin, a mathe- 

 matical physicist who needs no introduction to this audience] of questioning the 

 reality of anything unobservable is one of the greatest revolutions in scientific 

 thought that has ever occurred. * * * The great idea which Einstein con- 

 tributed to scientific philosophy was the principle that if a thing is essentially un- 

 observable then it is not a real thing and our theories must not include it. 5 



This remark has caught the eye of Mr. Albert Eagle, now a mathema- 

 tician but in his better days an experimental physicist, whoso name is 

 known wherever spectroscopy is practiced. 



To me, [says Mr. Eagle] this "great idea" is the most savage example of the 

 application of what is known as the principle of Occam's Razor of which I have 

 heard. * * * Einstein's "great idea" requires us to surrender our common- 

 sense for the sake of an arbitrary dictum of his which he and his followers have 

 raised to a fetish. It is preposterous, and to my way of thinking is so inherently 

 idiotic that I cannot understand anyone wasting his breath in giving utterance 

 to such a view. If I had first heard this opinion uttered at a scientific meeting 

 by some scientific nonentity I should have longed to have got up and said that 

 in my opinion such a view was simply a bit of perverse imbecility. 8 



And finally, here is the attitude of another philosopher, Rudolf 

 Carnap — perhaps the leading exponent of the most active of modern 

 schools of philosophy, the so-called "logical positivism." Carnap, 

 the philosopher, not only accepts the principle; he uses it to reduce 

 to nonsense those branches of his own subject known as metaphysics 

 and ethics. 



I will call metaphysical, [he writes] all those propositions which claim to present 

 knowledge about something which is over and above all experience. * * * 

 Metaphysicians * * * are compelled to cut all connection between their 

 propositions and experience; and precisely by this procedure they deprive them 

 of any sense. 7 



In these days, when politeness in controversy, so desirable and 

 proper if directed to the disputants, is so often improperly extended 

 to their ideas, so that few dare speak disrespectfully even of the 

 equator, there is something refreshing in the forthright character 

 of these remarks. And not only are they refreshing; they are highly 

 significant also. When men who are neither fools nor liars agree 

 that a certain idea is either the greatest discovery of a generation or 



• The new conceptions of matter, pp. 23, 81, 1931. 



• The philosophy of religion versus the philosophy of science, pp. 169-70 (1935). 

 » Philosophy and logical syntax, pp. 15, 17-18, 1935. 



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