Gustav Theodor Fechner comparing a rough and a cut diamond

What cutting teaches a diamond

Gustav Theodor Fechner (1801–1887) was a German physicist and philosopher. He asks what follows if his daylight view of the world extends even to a crystal. There is humour in his account of the passage from rough to cut diamond.

Turned against the light

Turn a crystal and its colour and brilliance change. Fechner asks where these changing impressions belong. His thought experiment begins with the distinctive way in which one particular body refracts light.

And so the diamond would have the loveliest of all these little souls, the cut diamond even one shaped and ennobled by education; loveliest of all if it is the diamond on the finger of a woman who has a still higher and lovelier soul in the head above it.

– Gustav Theodor Fechner, Die Tagesansicht gegenüber der Nachtansicht, p. 87.[1]

Where the comparison ends

In the next paragraph Fechner denies the diamond memory and reflection. This sharpens his use of “education”: the cut changes the appearance of light without giving the stone the life history of its wearer.