The mind in that mysterious instant Shelley likened beautifully to a fading coal. The instant wherein that supreme quality of beauty, the clear radiance of the esthetic image, is apprehended luminously by the mind which has been arrested by its wholeness and fascinated by its harmony is the luminous silent stasis of esthetic pleasure, a spiritual state very like to that cardiac condition which the Italian physiologist Luigi Galvani, using a phrase almost as beautiful as Shelley's, called the enchantment of the heart.