would, however, be
foolish to waste more time over a speculation so remote.

But these two facts remain unshaken:--(1) That our measurements and
whole science of Time depend absolutely on the operation throughout
Nature of the Law of Periodicity, and (2) that the periodicities which
affect and determine animal and vegetal life upon our Earth are the
periodic movements of rotation and revolution of that Earth itself.

Now it is to the curvilinear motions of the heavenly bodies that we must
ascribe our subjection to the periodic law. If these heavenly bodies
moved for ever in straight lines, as they would do if unacted on by
natural forces, the periodic rhythm of Nature would disappear.

It is to the fact that all Nature is under the constraint due to the
constant silent operation of physical Force that we owe, therefore, the
law which determines the most essential features of vitality. The
pulsations in which life consists and by which it is sustained are
attributable to the constraint and limitation which we recognise as the
effect of the operation of Natural Force. It is to this same cause that
we ascribe the resistance of cohering masses in virtue of which
sensation arises and by which our experience is punctuated. It is by
means of these obstructions to free activity that our experience is
denoted, and by reference to these that it is cognised. Indeed, Activity
itself as we know it depends upon and presupposes the existence of
these cohering masses.

Thus the operation of Natural Force and the constraint and limitation
which are thereby imposed upon our activity appear at once to determine
the conditions of life and to furnish the fundamental implements of
Knowledge.

We cannot overleap the barriers by which Life is constrained. These,
whilst, on the one hand they seem to _create the environment_ which
sustains Life, on the other hand seem to impose upon it the limitations
under which it inevitably fails and dies. We cannot even in imagination
conceive, either as reality or as fancy, the illimitable puissance of a
Life perfectly free and unrestrained. Yet the assurance that Perfect
Love could overcome the bonds of Materiality and Death encourages in
mankind the Hope of an existence beyond the impenetrable veil of
physical limitation. And this at any rate may be admitted, namely, that
that dynamic condition in which materiality arises is also the
condition-precedent of Tridimensionality, of Force, of Time, and o