On Cycles.
The one faith on which all normal
living beings consciously or unconsciously act, is
that like antecedents will be followed by like consequents.
This is the one true and catholic faith, undemonstrable,
but except a living being believe which, without doubt
it shall perish everlastingly. In the assurance
of this all action is taken.
But if this fundamental article is
admitted, and it cannot be gainsaid, it follows that
if ever a complete cycle were formed, so that the
whole universe of one instant were to repeat itself
absolutely in a subsequent one, no matter after what
interval of time, then the course of the events between
these two moments would go on repeating itself for
ever and ever afterwards in due order, down to the
minutest detail, in an endless series of cycles like
a circulating decimal. For the universe comprises
everything; there could therefore be no disturbance
from without. Once a cycle, always a cycle.
Let us suppose the earth, of given
weight, moving with given momentum in a given path,
and under given conditions in every respect, to find
itself at any one time conditioned in all these respects
as it was conditioned at some past moment; then it
must move exactly in the same path as the one it took
when at the beginning of the cycle it has just completed,
and must therefore in the course of time fulfil a
second cycle, and therefore a third, and so on for
ever and ever, with no more chance of escape than
a circulating decimal has, if the circumstances have
been reproduced with perfect accuracy.
We see something very like this actually
happen in the yearly revolutions of the planets round
the sun. But the relations between, we will
say, the earth and the sun are not reproduced absolutely.
These relations deal only with a small part of the
universe, and even in this small part the relation
of the parts inter se has never yet been reproduced
with the perfection of accuracy necessary for our
argument. They are liable, moreover, to disturbance
from events which may or may not actually occur (as,
for example, our being struck by a comet, or the sun’s
coming within a certain distance of another sun),
but of which, if they do occur, no one can foresee
the effects. Nevertheless the conditions have
been so nearly repeated that there is no appreciable
difference in the relations between the earth and
sun on one New Year’s Day and on another, nor
is there reason for expecting such change within any
reasonable time.
If there is to be an eternal series
of cycles involving the whole universe, it is plain
that not one single atom must be excluded. Exclude
a single molecule of hydrogen from the ring, or vary
the relative positions of two molecules only, and
the charm is broken; an element of disturbance has
been introduced, of which the utmost that can be said
is that it may not prevent the ensuing of a long series
of very nearly perfect cycles before similarity in
recurrence is destroyed, but which must inevitably
prevent absolute identity of repetition. The
movement of the series becomes no longer a cycle,
but spiral, and convergent or divergent at a greater
or less rate according to circumstances. We
cannot 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 cycular
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 phenomena
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 cycle of the relations between the earth
and sun. Let the first periodically recurring
substance—we will say A—be able
to recur or reproduce itself, not once only, but many
times over, as A1, A2, &c.; let A also have consciousness
and a sense of self-interest, which qualities must,
ex hypothesi, be reproduced in each one of its offspring;
let these get placed in circumstances which differ
sufficiently to destroy the cycle in theory without
doing so practically—that is to say, to
reduce the rotation to a spiral, but to a spiral with
so little deviation from perfect cycularity as for
each revolution to appear practically a cycle, though
after many revolutions the deviation becomes perceptible;
then some such differentiations of animal and vegetable
life as we actually see follow as matters of course.
A1 and A2 have a sense of self-interest as A had,
but they are not precisely in circumstances similar
to A’s, nor, it may be, to each other’s;
they will therefore act somewhat differently, and
every living being is modified by a change of action.
Having become modified, they follow the spirit of
A’s action more essentially in begetting a creature
like themselves than in begetting one like A; for
the essence of A’s act was not the reproduction
of A, but the reproduction of a creature like the one
from which it sprung—that is to say, a creature
bearing traces in its body of the main influences
that have worked upon its parent.
Within the cycle of reproduction there
are cycles upon cycles in the life of each individual,
whether animal or plant. Observe the action
of our lungs and heart, how regular it is, and how
a cycle having been once established, it is repeated
many millions of times in an individual of average
health and longevity. Remember also that it is
this periodicity—this inevitable tendency
of all atoms in combination to repeat any combination
which they have once repeated, unless forcibly prevented
from doing so—which alone renders nine-tenths
of our mechanical inventions of practical use to us.
There is no internal periodicity about a hammer or
a saw, but there is in the steam-engine or watermill
when once set in motion. The actions of these
machines recur in a regular series, at regular intervals,
with the unerringness of circulating decimals.
When we bear in mind, then, the omnipresence
of this tendency in the world around us, the absolute
freedom from exception which attends its action, the
manner in which it holds equally good upon the vastest
and the smallest scale, and the completeness of its
accord with our ideas of what must inevitably happen
when a like combination is placed in circumstances
like those in which it was placed before—
when we bear in mind all this, is it possible not to
connect the facts together, and to refer cycles of
living generations to the same unalterableness in
the action of like matter under like circumstances
which makes Jupiter and Saturn revolve round the sun,
or the piston of a steam-engine move up and down as
long as the steam acts upon it?
But who will attribute memory to the
hands of a clock, to a piston-rod, to air or water
in a storm or in course of evaporation, to the earth
and planets in their circuits round the sun, or to
the atoms of the universe, if they too be moving in
a cycle vaster than we can take account of? {160}
And if not, why introduce it into the embryonic development
of living beings, when there is not a particle of
evidence in support of its actual presence, when regularity
of action can be ensured just as well without it as
with it, and when at the best it is considered as
existing under circumstances which it baffles us to
conceive, inasmuch as it is supposed to be exercised
without any conscious recollection? Surely a
memory which is exercised without any consciousness
of recollecting is only a periphrasis for the absence
of any memory at all.