The Metaphysics of a Naturalist 
69 
and from objects. Secondarily we gauge them as they go from 
and approach us. The born blind, on recovering their sight, 
seem to lack depth in their space. 
The axes of reference, fore-aft, right-left, up-down, are partly 
gravitational and partly anatomical, and do not express the 
dynamic standards actually employed by the mind (for example, 
in the metageometry, with its fourth and even N dimensions). 
Now, says Hinton (in his book on The Fourth Dimension), if 
some hypothetical plane (two-dimensional) being should be in- 
formed of the existence of a third dimension and it were explained 
to him that a cube could be thought of as a square repeated in 
this third dimension an infinite number of times, or as a square 
moving in a certain unknown (to him) direction for a certain 
period, we get some notion of what the fourth dimension is to 
us who live in three dimensions. 
So in the case of the fourth dimension, there may be a direc- 
tion normal to all three of the known dimensions in which move- 
ment is possible ; and, in the absence of the ability to make molar 
motions in that direction in the ordinary way, we can form no 
notion of the fourth dimension. It does not become a dimension 
or spatial element, but must be represented in temporal or 
intentional terms. Physical research seems to prove that there 
are ^Things doing” in nature that cannot be conceived of as 
done in tridimensional space, and this fact gives zest and meaning 
to this metageometry. 
The metageometry seems to show us that moving to infinity 
in a radius drawn from my organism as the center of experience 
would be to return to the starting-point— that going far enough 
from self as a center would be to return — that is, the radius, after 
all, is but a great circle of the universe. 
We call motions molar which are capable of giving rise to space 
conceptions. Molecular and intramolecular motions, cohesion, 
gravitation, etc., do not produce these perceptions directly. If 
the speculations with reference to vortex activity, which is 
supposed to give to energy the static character constituting 
materiality, are to be trusted, we may have in these the clue to 
the fourth dimension. 
24. Causation as such cannot be defined, because it does not 
exist in the form of a plurality of causes. What does exist is 
.such an indissoluble linking together of all realities in fixed rela- 
