I had an optometrist appointment today, and also a dentist check-up. As I was sitting in a darkened room full of mysterious machines, it occurred to me to wonder just how it came to seem normal and comfortable to blindly obey the minute commands of a woman I had never met before: Look this way, look that way; keep your eyes open, blink if you need to; lean back; put your chin here. . . The optometrist tells you where to look, what to see. Then she changes what you see, changes even your ability to see. You don't know what that little bottle whose contents she wants to drip into your eye may hold. Numbing drops, she says--but it could be anything, acid, something to blind you, something to disease you.
I sit there in the leather armchair, lean forward when she tells me to. I stay put and try to keep my eyes from fluttering closed as a long blue tube approaches my eyeball ("to check your eye pressure"). It comes closer, closer, closer--will it touch my eye? puncture its orb? That trust: to be there, utterly relaxed and unworried, as she stares into your eye, face close to yours--far closer than you would ever let a random stranger in another environment come to your face: that total trust with your very eyes, your window onto the world, does not come naturally.
Same situation for the dentist. Lie back in the chair, open your mouth, let the oral hygienist scratch and prod your gums and teeth. You don't know what she's putting in her mouth, what's in that mint-flavored tooth polish junk.
Of course, the optometrist didn't put my eye out or blind me, and the dentist didn't poison me. But honestly, you have no real way of knowing that she won't, when you sit down in her chair and she closes the door. You simply trust her not to harm you. You trust her to do her job well and bear you no ill will: this complete stranger. You entrust your body to her--temporarily, but blindly nonetheless. You do this when you go into surgery, when you take a train, when you buy medicine or food, when you rent a house, when you venture onto the road. . . You have to trust complete strangers to be sane. Where does that trust come from?
It comes from the lessons of parents, first, and later from the assurance of licensing and from the power that you hold, as a citizen with the right to sue for malpractice. It's a social thing, this trust. The social contract, perhaps: the fabric of society.