But, in fact, who we think we are is intertwined with our notions of who everyone else is.
Our concept of "the other" is at the root of our own sense of identity.
We define ourselves, to a large extent, in terms of who or what we are not.
A newborn experiences no boundary between herself and the rest of the world. To her, all is buzzing confusion within a chaos of sensations.
In time, she learns that the nipple on which she feeds is not an extension of herself. She begins to find the boundaries of her own body and, in time, even to gain some control over them. And eventually to form what is called "a theory of mind," the understanding that she cohabits the world with other sentient beings who have thoughts and feelings similar to her own.
Of course, this is obviously a gross over-simplification, but the key idea is that our self-identity is plastic and develops over our entire lifetime in response to our experience of the world around us. Our sense of "self" and our sense of the "other" are symbiotic.
So what does it mean when a French president says that his country faces an "identity crisis" because of all the Asians, Africans and Muslims crowding into his country? What should we make of Talmudic arguments over the definition of a "Jew." And how about the Dutch editor who complained, "We want to teach immigrants more about our identity, and we discover that we're not sure what's left of it"?
One writer, Van Wishard of WorldTrends Research, thinks it's all a sign of a "global identity crisis."
The concept of the "other" has a long and storied history in philosophy and psychology. But this is more than idle philosophizing or armchair therapy.It's a matter of life and death for millions.
As Van Wishard points out, the problem of the other is behind the ethnic strife that has cursed large swaths of the developing world. And, perhaps, a preview of coming attractions for the rest of us.