axes and one time axis of reference, they be referred to a set of
four interchangeable axes involving four homogeneous co-ordinates.
In other words, _time_ is made the fourth dimension. Psychic
phenomena indicate that occasionally, in some individuals,
the will is capable of producing physical movements for whose
geometrico-mathematical definition a four-dimensional system of
co-ordinates is necessary. This is only another step along the road
which the human mind has always travelled: our conception of the
cosmos grows more complete and more just at the same time that it
recedes more and more beneath the surface of appearances.

Far from the Higher Space Hypothesis complicating thought, it
simplifies by synthesis and co-ordination in a manner analogous to
that by which plane geometry is simplified when solid geometry
becomes a subject of study. By immersing the mind in the idea of
many dimensions, we emancipate it from the idea of dimensionality.
But the mind moves most readily, as has been said, in ordered
sequence. Frankly submitting ourselves to this limitation, even
while recognizing it as such, let us learn such lessons from it as
we can, serving the illusions that master us until we have made them
our slaves.




II THE DIMENSIONAL LADDER


LEARNING TO THINK IN TERMS OF SPACES