14. Space of Perception. As already stated in the
Introduction, the space of John Locke led to the a priori
space of Immanuel Kant, which is a durable creation
indeed. But Kant unnecessarily (Spengler, I, 170-71)
and imprudently fused it with Euclidean space; and
partisans of Kant do not quite know how to disembar-
rass themselves of the fact that mathematics of the
nineteenth century constructed other spaces, and
physics of the twentieth century adopted some of these.
In the first half of the nineteenth century, psychology
became experimental psychology and broke away from
philosophy. This brought into being a space of psy-
chology and physiology to which the Victorian era was
very attentive (H. Weyl, secs. 14 and 18). Thus,
H. L. F. Helmholtz investigated the mathematical struc-
ture of the space of experience under certain assump-
tions of “free mobility,” in his dual capacity of physicist
and physiologist.
An active preoccupation with the space of psychol-
ogy continued into the beginnings of the twentieth
century. Thus, a two-volume treatise of the psycholo-
gist William James had a chapter (20) of 150 pages
on “the perception of space.” But, not long afterwards,
psychology began to lose interest in space as the
Victorian age had known it, and all that it still wanted
to know about space were such un-Kantian topics as:
Visual angle, Monocular Movement, Parallax, Stereo-
scopic vision, etc. A very voluminous Handbook from
around mid-twentieth century (S. S. Stevens) devotes
only 30 pages out of 1435 to the topic of space.
