Page:Mind-a quarterly review of psychology and philosophy, vol33, no129 (1924).djvu/7

 3. It is obvious that such a lack of uniformity in its fundamental concepts cannot be very beneficial to a science; to what confusion it can lead is known to every reader of the popular and semi-popular expositions to which Einstein’s theory gave rise. Space and time begin to warp, to stretch, to shrink, and to pass through all possible deformations, without any knowledge on the part of the writer or reader what a deformation of space and time means or can mean.

The present study is an attempt to arrive at a logically satisfactory definition of space and time which would also satisfy the requirements of physics. To accept space and time as undefined fundamental concepts of physics is not possible, owing to the previously mentioned lack of agreement as to their meaning; it is therefore necessary to derive them from some more fundamental and undefined concepts, as to the meaning of which there exists no such divergency of opinions.

4. The majority of definitions which have undertaken this task are very unsatisfactory; some, because they are logically defective, like the one mentioned above, others, because they yield nothing to our knowledge of physics, and hence are useless for its purpose. The answers given to the problem of defining space and time by the philosophers are mostly inadequate because, instead of a definition applicable to physics, they attempt to ascertain the metaphysical status of these two concepts; so, e.g., Kant’s famous attempt.

The present study is based upon the point of view that all ontological or metaphysical speculations are entirely and completely irrelevant to physics; physics produces its laws irrespective of whether the entities described by them are realities existing outside the mind, or merely its products. The truth of a given law of gravitation remains unaffected, whether we presuppose that the bodies subject to it are real things, existing even when we do not exist, or that they are an illusion of our mind.

5. Physical science is conditioned by perception; in perception it has its roots, percepts form its material, which it arranges, analyses and “explains” by reducing them to the smallest attainable number of elementary (i.e., further irreducible) percepts and relations.

The conception of percept is here to be understood in a