1907-8.] SPACE AND Its DIMENSIONS. 335 
constitutes the spacial, and the whole reduction to fusion of quality and 
quantity is in vain. Any kind of ‘‘local’’ colouring, no matter how it is 
defined, presupposes space. Wundt’s theory of the fusion of quantitative 
and qualitative local signs, which, as we shall see below, renders excellent 
service towards the solution of the third problem, that about the definite 
localization in space, necessitates a certain modification in order to make 
it unimpeachable also with regard to the second problem. For this 
purpose one needs only to drop the pre-supposition that the specific 
qualitative differences which constitute the local colouring are originally 
of a non spacial character. On the contrary one must assume that these 
quality differences are toto genere different from all other quality differ- 
ences. In other words we must assume that the difference between all 
other qualities on the one side, and space on the other side is greater 
than the differences of the other qualities from one another. In other 
words that the differences between the other qualities and those qualities 
which constitute space is a difference of higher order. But then we can 
just as well say these specific qualities are space. 
Thus we see, that which is the essential in extension is not magnitude, 
intensity, but something qualitative. The characteristic quality cannot 
be otherwise expressed than by propositions like the following ones,— 
“This is not that,” ‘‘This place is not that place,” ‘This direction is not 
that direction,” etc. The realm of this continuous manifoldness whose 
qualities are more different from the qualities of sensations and emotions 
than these are among themselves is space. Space is simple and directly 
given and consequently can never be defined or explained (i.e. reduced to 
. something simpler.) All attempts to deduce space from the non-spacial 
must consequently lead to insolvable contradictions. 
The third problem concerns the definite and unambiguous order of 
spacial perceptions and presentations, and it is here that Wundt’s theory 
of complex local signs offers the best conceivable description of the facts 
and even does not fail when facing the more intricate problems of 
vision, the binocular and monocular perception of depth. The order of 
our spacial perceptions is accomplished through the co-operation of the 
qualities of extension originally given, with different systems of intensive 
elements. On the basis of the former we distinguish locations and direc- 
tions and by means of the latter we estimate magnitudes and distances. 
Thus spacial distinction is a priori, but space measurement is a posteriori. 
Just here we must admit that the expressions a priori, and a posteriori are 
from the theory of knowledge standpoint just as objectionable as the terms, 
innate and acquired. If these terms are not to be taken in a purely tempor- 
al sense they must be defined with due regard to their relation (dependence 
