with a sound but half its own

The everlasting universe of Things
Flows through the Mind, and rolls its rapid waves,
Now dark—now glittering—now reflecting gloom—
Now lending splendour, where from secret springs
The source of human thought its tribute brings
Of waters,—with a sound but half its own,
Such as a feeble brook will oft assume
In the wild woods, among the Mountains lone,
Where waterfalls around it leap for ever,
Where woods and winds contend, and a vast river
Over its rocks ceaselessly bursts and raves.

-- Percy Bysshe Shelley, lines from "Mont Blanc"

Mont Blanc: Lines Written in the Vale of Chamouni

Every scheme for the analysis of nature has to face these two facts, change and endurance. There is yet a third fact to be placed by it, eternality, I will call it. The mountain endures. But when after ages it has been worn away, it has gone. If a replica arises, it is yet a new mountain. A colour is eternal. It haunts time like a spirit. It comes and it goes. But where it comes, it is the same colour. It neither survives nor does it live. It appears when it is wanted. The mountain has to time and space a different relation from that which colour has.

-- Alfred North Whitehead Science and the Modern World