Consciousness is a born hermit.
When I was very young I acutely felt the isolation of consciousness. I have always been naturally unathletic; so in gym class I tired out very quickly. Reflecting on this, I wondered if the pain and fatigue I felt were somehow more intense than that experienced by my classmates. If, somehow, the consciousness of a more athletic student were projected into my body, would they feel my pain sensations as unbearably agonizing compared with what they were used to?
Reflections like this naturally led me to other questions. My father is colorblind; what does the world look like to him? And for that matter, how can we know what the world looks like to anybody? Does the red I see look the same as the red my brother sees? Without the ability to check our experiences against each other’s, we can never know, it seems, whether our experiences are truly similar or whether we simply use the same names for things.
Thinking along these lines, I tried to imagine what it would be like for another consciousness to inhabit my body. Would they recognize the world through my sensations, or would it be entirely alien to them? More chillingly, I sometimes wondered whether other minds existed at all. Certainly I never saw any. And what of the world? If reality could look different to any perceiving mind, how did it look “in itself”? Could all of us be deeply mistaken about the world we live in?
The suspicion that our senses are limited and untrustworthy was bolstered from my early interest in science. From books I learned that the fundamental organization of matter—molecules and elements and electrons—is only intelligible on a scale far beyond the finest reaches of our eyesight. I learned that the earth and everybody on it were a mere speck in the universe, and that our vision and even our imaginations were inadequate to the task of comprehending the true scales of things, large and small.
All this adds up to Santayana’s image of consciousness as a hermit: connected to reality through our unreliable sensations, fundamentally cut off from other minds, forever at a distance and in the dark, like a goldfish in a movie theater.
It was Descartes who initiated this solipsism with his famous skeptical method. And philosophers have been struggling with this set of problems ever since.
Santayana saw no rational way out of skepticism, and instead cut the gordian knot with his notion of “animal faith,” the irresistible animal impulse to act, survive, and socialize. This impulse notwithstanding, Santayana considered our knowledge of other minds to be purely speculative—a kind of guessing game in which one person imputes their thoughts onto another, blindly trusting that their friend’s basic constitution is similar enough to make their own reactions a good guide.
Proust was even more extreme in his views. For him all human relationships were just vain illusions, a tissue of self-delusion based on mutual misunderstanding. Indeed, for him it was impossible to really understand somebody else, at least through conventional means, and the path to reality lay through introspection alone.
Nowadays I am not so inclined to see humans as so inevitably isolated. We are social creatures to our cores. As Ludwig Wittgenstein and Gilbert Ryle persuasively argued, language—and significance more generally—is intrinsically public. For communication to be possible there must be a community of like-minded speakers.
By nature, too, we are open to the public. It takes effort to teach children to read silently; and indeed silent reading did not become habitual, historically speaking, until quite recently. This is just one example of a more general phenomenon: public behavior is the rule, private the exception.
Though it may be possible to doubt other minds in the speculative privacy of one’s study, doing so while looking into somebody’s eyes is another matter. Subtle movements of muscle—the crinkling of the eyes, the knitting of the brow, the pursing of the lips, and a thousand other things that normally escape conscious attention—tell us, immediately and exactly, how other people are feeling.
Of course it is possible to be mistaken; and of course the exact situation motivating the emotional response might be impossible to guess. But in general I think that most people, most of the time, are sufficiently aware of other people’s emotional states.
Indeed, the natural tendency to display emotions is so strong that it takes years of social training to allow citizens of dense urban civilizations to suppress these signals enough to get along in society. Our modern world, in which we must daily interact with strangers and acquaintances, requires that we leave unexpressed many passing emotions. But this situation is, evolutionarily speaking, extremely recent, and one which is not “natural” to our species.
To put this another way, I think that Santayana greatly underestimated the degree to which we are fundamentally similar, and did not fully grasp the strength of our unmediated, instinctive social behavior. This was natural for him, since Santayana was known for being himself a born hermit—aloof and solitary. So although we can never know whether another person’s experiences are the same as our own, we have good reason to believe they are not fundamentally different.