anging the meaning of your terms as you proceed
with your description, you are bound to take one of these sets of axes
as axes of reference; though you may choose their reflections into the
space of any time-system which you wish to adopt. A definite physical
reason is thereby assigned for the peculiar property of the dynamical
group of axes.

On the orthodox theory the position of the equations of motion is most
ambiguous. The space to which they refer is completely undetermined and
so is the measurement of the lapse of time. Science is simply setting
out on a fishing expedition to see whether it cannot find some procedure
which it can call the measurement of space and some procedure which it
can call the measurement of time, and something which it can call a
system of forces, and something which it can call masses, so that these
formulae may be satisfied. The only reason--on this theory--why anyone
should want to satisfy these formulae is a sentimental regard for
Galileo, Newton, Euler and Lagrange. The theory, so far from founding
science on a sound observational basis, forces everything to conform to
a mere mathematical preference for certain simple formulae.

I do not for a moment believe that this is a true account of the real
status of the Laws of Motion. These equations want some slight
adjustment for the new formulae of relativity. But with these
adjustments, imperceptible in ordinary use, the laws deal with
fundamental physical quantities which we know very well and wish to
correlate.

The measurement of time was known to all civilised nations long before
the laws were thought of. It is this time as thus measured that the laws
are concerned with. Also they deal with the space of our daily life.
When we approach to an accuracy of measurement beyond that of
observation, adjustment is allowable. But within the limits of
observation we know what we mean when we speak of measurements of space
and measurements of time and uniformity of change. It is for science to
give an intellectual account of what is so evident in sense-awareness.
It is to me thoroughly incredible that the ultimate fact beyond which
there is no deeper explanation is that mankind has really been swayed by
an unconscious desire to satisfy the mathematical formulae which we call
the Laws of Motion, formulae completely unknown till the seventeenth
century of our epoch.

The correlation of the facts of sense-experience effected by the
alternative