I went down to the laboratory; it was empty. The sound of my steps on the white tiles echoes dolefully in the room. Around me, the flasks, test tubes, and retorts had a stubborn, hostile look. I went over to the microscope. Marianne had spread a fine golden powder on one of the slides. I knew it would make her happy if I were able to give her an exact description of it. But as for me, I no longer had any illusions —I would never break through the crusty surface of the apparent world. Even with the aid of microscopes and telescopes, it was still only with my eyes that I saw things; objects existed for us only because they were visible, tangible, prudently situated in space and time amid other objects. Even if we were to fly to the moon, or go down to the bottom of oceans, we would still be men in the heart of a human world. As for those mysterious realities which revealed themselves to our senses —forces, planets, molecules, waves —they were hidden by words and protected by the yawning gap of our ignorance. Never would nature deliver up to us her secrets; she had no secrets. We were the ones who invented questions and then formulated the answers to them; in the bottoms of our retorts we would never discover anything but our own thoughts, thoughts that might in the course of centuries multiply, become more complex, be formed into vaster and more subtle systems. But never would these thoughts be capable of tearing me from myself. I put my eye to the microscope; everything would always pass through my eyes, through my thoughts. Never would anything be something else, never would I be someone else.
—Simone de Beauvoir, All Men Are Mortal, p. 276