t conceive of all the atoms in the universe standing twice over
in absolutely the same relation each one of them to every other. There
are too many of them, and they are too much mixed; but, as has been just
said, in the planets and their satellites we do see large groups of atoms
whose movements recur with some approach to precision. The same holds
good also with certain comets and with the sun himself. The result is
that our days and nights and seasons follow one another with nearly
perfect regularity from year to year, and have done so for as long time
as we know anything for certain. A vast preponderance of all the action
that takes place around us is cyclical action. Within the great cycle of
the planetary revolution of our own earth, and as a consequence thereof,
we have the minor cycle of the seasons; these generate atmospheric
cycles. Water is evaporated from the ocean and conveyed to
mountain-ranges, where it is cooled, and whence it returns again to the
sea. This cycle of events is being repeated again and again with little
appreciable variation. The tides, and winds in certain latitudes, go
round and round the world with what amounts to continuous regularity.
There are storms of wind and rain called cyclones. In the case of these,
the cycle is not very complete, the movement, therefore, is spiral, and
the tendency to recur is comparatively soon lost. It is a common saying
that history repeats itself, so that anarchy will lead to despotism and
despotism to anarchy; every nation can point to instances of men's minds
having gone round and round so nearly in a perfect cycle that many
revolutions have occurred before the cessation of a tendency to recur.
Lastly, in the generation of plants and animals we have, perhaps, the
most striking and common example of the inevitable tendency of all action
to repeat itself when it has once proximately done so. Let only one
living being have once succeeded in producing a being like itself, and
thus have returned, so to speak, upon itself, and a series of generations
must follow of necessity, unless some matter interfere which had no part
in the original combination, and, as it may happen, kill the first
reproductive creature or all its descendants within a few generations. If
no such mishap occurs as this, and if the recurrence of the conditions is
sufficiently perfect, a series of generations follows with as much
certainty as a series of seasons follows upon the cyc