JOURNAL 
OF THE 
WASHINGTON ACADEMY OF SCIENCES 
Vou. 13 May 19, 1923 | No. 10 
MATHEMATICS.—The reduction of all physical dimensions to those 
of space and time. A. P. MaruEws,! University of Cincinnati. 
To reduce the number of different kinds of things has been the 
general course of development of science. Thus in chemistry the 
diverse substances on the earth’s surface have been found to be com- 
posed of about 100 simpler substances or elements; and these elements, 
in their turn, of different numbers of positive and negative electrons. 
Similarly the forms of radiant energy—heat, light, X-rays, electro- 
magnetic waves—have all been reduced to one kind differing only in 
size. So also in the case of those other entities with which physics 
deals—electricity, magnetism, force, energy, matter, heat—increase of 
knowledge has enabled a considerable simplification accompanied by 
a clarification of ideas. 
The end of this movement must be to express the physical entities 
of the universe in the terms of the four dimensions, three of space and 
that of time. With these four dimensions we should then be able to 
write the whole of the physical universe in the equations of a four 
. dimensional space. 
There is, to be sure, a fifth dimension, which we must at present 
conserve, namely, the unknown dimensions of psychism. By psychism 
I mean that property of matter, at present neglected by the physicist, 
which is exhibited in its clearest form in living things and which shows 
itself in thought and consciousness in such large psychic units as 
ourselves. The course of evolution of living beings has been such as to 
create larger and more perfect psychic units. We might formulate 
the general law that the course of evolution was in the direction of 
increase of psychism. If we put P for the undetermined dimensions 
of psychism,—the unknown, and usually unrecognized, psychic factor 
1 Received, April 12, 1923. 
195 
