A. THE MUTABILITY OF THE COSMOS

The Fact of Mutability

(a) in the macrocosm:

12. At first sight it is rightly a source of wonderment to recognize how the knowledge of the fact of mutability has gained ever greater ground, both in the macrocosm and in the microcosm, according as science has made new progress, as though confirming with new proofs the theory of Heraclitus: "Everything is in flux": panta rhei. As is known, our own everyday experience brings to light an immense number of transformations in the world around us, both near and far away, particularly the local movements of bodies.

13 But, over and above all, these local movements strictly so called, the manifold chemico-physical changes which take place in the world are equally noticeable, as, for example, the change in the physical state of water in its three phases of steam, liquid, and ice. We are aware also of the far-reaching chemical effects produced by the use of fire, the knowledge of which goes back to pre-historic times, and of the weathering or rocks and the corruption of vegetable and animal life.

14. This common experience is corroborated by the natural sciences, which have taught people to understand these and other similar changes as processes of destruction and construction of corporeal substances in their chemical elements, that is to say, in their tiniest parts, the chemical atoms. Going still farther, natural science made known that this chemico-physical mutability is not, as the ancients thought, restricted to terrestrial bodies, but even extends to all the bodies of our solar system and of the great universe, which the telescope, and still more the spectroscope, have demonstrated to be composed of the same kind of atoms.