One must always maintain one's connection to the past and yet ceaselessly pull away from it. To remain in touch with the past requires a love of memory. To remain in touch with the past requires a constant imaginative effort.

Any work of science, no matter what its point of departure, cannot become fully convincing until it crosses the boundary between the theoretical and the experimental: Experimentation must give way to argument, and argument must have recourse to experimentation.

If there is any realm where distinction is especially difficult, it is the realm of childhood memories, the realm of beloved images harbored in memory since childhood. These memories which live by the image and in virtue of the image become, at certain times of our lives and particularly during the quiet age, the origin and matter of a complex reverie: the memory dreams, and reverie remembers.

He who ceases to learn cannot adequately teach.

It is not a question of observation which propels mankind forward as if toward a looking glass of great magnitude; it is an instance of aggrandized reflection that insinuates the human psyche to the inhuman.

To go upstairs in the word house is to withdraw step by step; while to go down to the cellar is to dream.

The repose of sleep refreshes only the body. It rarely sets the soul at rest.