The idea that the whole human race is, in a sense, one thing —one huge organism, like a tree—must not be confused with the idea that individual differences do not matter or that real people, Tom and Nobby and Kate, are somehow less important than collective things like classes, races, and so forth.
Indeed the two ideas are opposites. Things which are parts of a single organism may be very different from one another: things which are not, may be very alike. Six pennies are quite separate and very alike: my nose and my lungs are very different but they are only alive at all because they are parts of my body and share its common life. Christianity thinks of human individuals not as mere members of a group or items in a list, but as organs in a body—different from one another and each contributing what no other could. When you find yourself wanting to turn your children, or pupils, or even your neighbours, into people exactly like yourself, remember that God probably never meant them to be that. You and they are different organs, intended to do different things.
On the other hand, when you are tempted not to bother about someone else’s troubles because they are “no business of yours,” remember that though he is different from you he is part of the same organism as you. If you forget that he belongs to the same organism as yourself you will become an Individualist. If you forget that he is a different organ from you, if you want to suppress differences and make people all alike, you will become a Totalitarian. But a Christian must not be either a Totalitarian or an Individualist.
I feel a strong desire to tell you—and I expect you feel a strong desire to tell me—which of these two errors is the worse. That is the devil getting at us. He always sends errors into the world in pairs—pairs of opposites. And he always encourages us to spend a lot of time thinking which is the worse. You see why, of course? He relies on your extra dislike of the one error to draw you gradually into the opposite one. But do not let us be fooled. We have to keep our eyes on the goal and go straight through between both errors. We have no other concern than that with either of them.
-C.S. Lewis, Mere Christianity, Bk. 4, 6