幸福是一种内在的工作。

What do we call visible light? We call it color. But the colors are only the names we give to the way light behaves when it hits something.

The mathematician's patterns, like the painter's or the poet's, must be beautiful; the ideas, like the colors or the words, must fit together in a harmonious way.

I am certain of nothing but the holiness of the heart's affections, and the truth of imagination.