This movement has been chosen
by it as representative of time, and it is, by definition, uniform. Let
us call T_{1}, T_{2}, T_{3}, ... etc., points which divide the trajectory
of the mobile into equal parts from its origin T_0. We shall say that 1, 2,
3, ... units of time have flowed past, when the mobile is at the points
T_{1}, T_{2}, T_{3}, ... of the line it traverses. Accordingly, to consider
the state of the universe at the end of a certain time _t_, is to
examine where it will be when T is at the point T_t of its course. But
of the _flux_ itself of time, still less of its effect on consciousness,
there is here no question; for there enter into the calculation only the
points T_{1}, T_{2}, T_{3}, ... taken on the flux, never the flux itself.
We may narrow the time considered as much as we will, that is, break up at
will the interval between two consecutive divisions T_{n} and T_{n-|-1};
but it is always with points, and with points only, that we are dealing.
What we retain of the movement of the mobile T are positions taken on
its trajectory. What we retain of all the other points of the universe
are their positions on their respective trajectories. To each _virtual
stop_ of the moving body T at the points of division T_{1}, T_{2}, T_{3},
... we make correspond a _virtual stop_ of all the other mobiles at the
points where they are passing. And when we say that a movement or any
other change has occupied a time _t_, we mean by it that we have noted a
number _t_ of correspondences of this kind. We have therefore counted
simultaneities; we have not concerned ourselves with the flux that goes
from one to another. The proof of this is that I can, at discretion,
vary the rapidity of the flux of the universe in regard to a
consciousness that is independent of it and that would perceive the
variation by the quite qualitative _feeling_ that it would have of it:
whatever the variation had been, since the movement of T would
participate in this variation, I should have nothing to change in my
equations nor in the numbers that figure in them.

Let us go further. Suppose that the rapidity of the flux becomes
infinite. Imagine, as we said in the first pages of this book, that the
trajectory of the mobile T is given at once, and that the whole history,
past, present and future, of the material universe is spread out
instantaneously in space. The same mathematical correspondences will
subsist between the moments of the history of