infer and
measure the transmutations of Energy, but the transmutations measured
are operations of the real thing-in-itself postulated by Science. The
existence of such Energy is suggested to me primarily in my experience
of my own activity in which I recognise my power of doing work--a
quantifiable and measurable thing, homogeneous with the Energy in
respect of which Science states the relations and conditions of all
physical phenomena. My most incessant mental act is that by which, on
the analogy of my own active experience, I refer all phenomena to the
underlying energetic system. This reference it is which transforms
sensation into perception; and the constant affirmation of this
reference is the great function of the synthetic mental activity of the
understanding, and is at once the origin and explanation of that
imperative mental tendency which metaphysicians call the law of
Causality.

How, then, does this doctrine affect the theory of the nature of Space?

If it be true that the world as my Presentment consists in the
transmutations occurring in that particular part of the energetic system
which constitutes the real substratum of the brain, then phenomena as a
whole must arise in transmutation, in a process of Becoming rather than
in a state of Being, and Space must be the content, the condition, in
which that process proceeds. The laws of Space, therefore, are laws, so
to speak, of motion, not of position. The most absolutely still and
motionless visual presentation is really a series of constant
transmutations of Energy and the form of Space is constituted by the
laws of transmutation, which are thus at once the necessary conditions
of my perception and the universal conditions of all sense-perception.
Space, therefore, does not contain the real thing which sustains the
phenomenal world any more than it does the reality which underlies my
conscious self. It is the universal condition of the transmutations
which constitute phenomena; and it therefore "contains" all these
phenomena, including my body as phenomenon and only as phenomenon. Its
form is discovered by my organic motor activity, and in representing
this activity the mind constructs its concepts of Space and Extension.

This view of the nature of Space, by relating its forms and laws with
the objective, and a-logical thing-in-itself in virtue of the
transmutations of which our sense-experience occurs, relieves an obvious
difficulty which must always