The dogma of original sin and the monotheistic fatherhood of God are the two elements comprising the bedrock of democracy, international justice, and human solidarity. If we are all ONE in Adam as sinners, no culture can justly oppress another as "worse" than itself, and if we are all ONE as creatures under the one good God, we have ethical solidarity rooted in the ontological unity of God.
It would be one thing to say "those guys" are all sinners. It's quite something else to say "we are all sinners redeemed under one God."
Then again, as one of my friends put it, how about "just shut the hell up and get along with each other"? But that's impossible, he concluded.
My point about human solidarity in sin and in salvation is historical, not philosophical, for the moment. Whether the theology of sin and redemption ought to ground human solidarity, or whether some other viewpoint can do the same as well, is a philosophical question. I am merely asserting that the historical basis of human solidarity as a political reality lies in the greatest theological pessimism and optimism. Historically, in other words, "we" is a theological concept. We are all in this together––both as a bunch of equally dastardly bastards and as a bunch of forgiven unforgivables. It is this difocal view of humans as unified in guilt and unified in grace that brought to fruition all the ideas of modern political harmony which we take for granted in secular ignorance. As Fulton J. Sheen puts it in The Life of All Living (New York: Image Books, 1979):
"Humanity can never be the object of religion for the very reason that a self-centered humanity would be just as chilling as a self-centered individual. Furthermore, there is no such thing as humanity, practically speaking. There are only men, only Peters and Pauls…. [I]t is nonsense to speak of altruism, if there be only humanity, for humanity has no 'alter,' no "other," toward which it can be beneficent. It is only when men call God 'Father,' that they can call one another 'Brother,' and God is not a Father unless He has a Son. Even the serpent in the garden knew that the service of humanity could never satisfy man. He tricked man, not by telling him he would be like other men, but that he would be like unto God" (p. 65).
But what if human solidarity is itself just a myth? Just a dogma without a basis in reality? What if the unredeemed pessimist is right, and history clearly teaches us that people simply don't get along with people?
Then, I'd have to ask, "Who are these 'people' of which the pessimist speaks?" Probably he has in mind Homo sapiens sapiens, the species that is social through and through. The animals that live together in harmonious social wholes––but allegedly "don't get along at all"?