1 8 2 D O C U M E N T 4 4 J U N E 1 9 2 0
2nd class tickets and accommodations in a very simple hotel (they may be very
small rooms), considering that I don’t place any importance on amenities. Please
also arrange for the travel permit on the part of the Norwegian state and take care
that I be immediately notified when I may obtain the Norwegian visa for me and
my daughter. I shall depart as soon as all the necessary formalities for the trip have
In great respect,
A. Einstein.
44. To Ernst Cassirer
Berlin, 5 June 1920
Highly esteemed Colleague,
I studied your treatise thoroughly and with very much interest and admired,
above all, how securely you master the essence of relativity
I made brief
comments in the margin where I was not completely in agreement. E.g., I could not
accept your opinion about the Kant-Newton relationship with reference to space
Newton’s theory requires an absolute (objective) space in order to be
able to attribute real meaning to acceleration, which Kant does not seem to have
I can understand your idealistic way of thinking about space and time and also
believe that one can thereby arrive at a consistent point of view. Not being a philos-
opher, the philosophical antitheses seem to me more conflicts of emphasis than
fundamental contradictions. What Mach calls connections [Verknüpfung] are for
you the ideal names that make experience possible in the first
You, how-
ever, emphasize this aspect of knowledge, whereas Mach wants to have it appear
as insignificant as possible. I acknowledge that one must approach experiences
with some sort of conceptual tool in order for science to be possible; but I do not
think that our choice of these tools is constrained by virtue of the nature of our in-
tellect. Systems of concepts seem empty to me, if the way in which they are to be
related to experience is not laid down. This seems to me highly essential, even
though we often find advantage in theoretically isolating purely conceptual rela-
tions, in order to have the logically secured interdependencies come more cleanly
to the fore. With the interpretation of ds as a result of measurement that can be ob-
tained in a very specific way by means of measuring rods and clocks, the theory of
relativity stands and falls as a physical
I think that your treatise is very well suited to clarify philosophers’ ideas and
knowledge about the physical problem of relativity.
Best regards, yours,
Previous Page Next Page