214 HERBERT SPENCER

10. The multiplication of effects: every mass and part
of a mass on which a force falls sub-divides and differentiates
that force, which thereupon proceeds to work a variety of
changes • and each of these becomes the parent of similarly
multiplying changes: the multiplication of these becoming
greater in proportion as the aggregate becomes more hetero-
geneous. And these two causes of increasing differentiations
are furthered by—

11. Segregation, which is a process tending ever to
separate unlike units, and to bring together like units, so
serving continually to sharpen or make definite differentia-
tions otherwise caused.

12. Equilibration is the final result of these transformations
which an evolving aggregate undergoes. The changes go on
until there is reached an equilibrium between the forces
which all parts of the aggregate are exposed to, and the
forces these parts oppose to them. Equilibration may pass
through a transition stage of balanced motions (as in a
planetary system), or of balanced functions (as in a living
body), on the way to ultimate equilibrium ; but the state of
rest in inorganic bodies, or death in organic bodies, is the
necessary limit of the changes constituting evolution.

13. Dissolution is the counterchange which sooner or later
every evolved aggregate undergoes. Remaining exposed to
surrounding forces that are unequilibrated, each aggregate is
ever liable to be dissipated by the increase, gradual or sudden,
of its contained motion; and its dissipation, quickly under-
gone by bodies lately animate, and slowly undergone by
inanimate masses, remains to be undergone at an indefinitely
remote period by each planetary and stellar mass, which, since
an indefinitely remote period in the past, has been slowly
evolving: the cycle of its transformations being thus completed.

14. This rhythm of evolution and dissolution, completing
itself during short periods in small aggregates, and in the vast
aggregates distributed through space completing itself in
periods which are immeasurable by human thought, is, so far
as we can see, universal and eternal: each alternating phase
of the process predominating—now in this region of space,
and now in that—as local conditions determine.

15. All these phenomena, from their great features down