Haud igitur penitus pereunt quaecumque videntur,
Quando alid ex alio reficit natura nec ullam
Rem gigni patitur nisi morte adiuta aliena?[427]
As the 'ever-during peace' at the heart of all things is supposed to result from the eternal and immutable properties of the atoms, this 'endless agitation' arises out of their unceasing motion through infinite space. There are two kinds of motion,—the one tending to the renewal,—the other, to the destruction of things as they now exist. The maintenance of our whole system depends on the equilibrium of these opposing forces—
Sic aequo geritur certamine principiorum
Ex infinito contractum tempore bellum.[428]
There is thus seen to be not only absolute order, but also infinite change in the processes of Nature. Decay and renovation, death and life, support the existing creation in unceasing harmony. The imagination represents this process under the impressive symbol of an endless battle, in which now one side now the other gains some position, but neither, as yet, can become master of the field—
Nunc hinc nunc illic superant vitalia rerum,
Et superantur item.[429]