An excellent post by Bryan Caplan at EconLog examines the intentions of eugenics against the actual effects of the implementation of such policies. His point? “Even if genetics explained ALL differences in success, many policies that raise average genetic quality would backfire.”
The reason is the Law of Comparative Advantage, or the reality that “trade between two people or groups increases total production even if one person or group is worse at everything.” Read the whole post for his proof, using a hypothetical case of Brains vs. Brawn. He concludes: “The Law of Comparative Advantage shows that even if some people really are more productive than others in every respect, they have something to offer each other.”
Christians could recognize this reality as just one small piece of a vibrant biblical doctrine of the imago Dei, that every person is created in the image of God, and is of inestimable worth and dignity.
In this regard, read the quote from C. S. Lewis’ sermon, “The Weight of Glory”:
There are no ordinary people. You have never talked to a mere mortal. Nations, cultures, arts, civilizations—these are mortal, and their life is to ours as the life of a gnat. But it is immortals whom we joke with, work with, marry, snub, and exploit—immortal horrors or everlasting splendours. This does not mean that we are to be perpetually solemn. We must play. But our merriment must be of the kind (and it is, in fact, the merriest kind) which exists between people who have, from the outset, taken each other seriously—no flippancy, no superiority, no presumption. And our charity must be real and costly love, with deep feeling for the sins in spite of which we love the sinners—no mere tolerance, or indulgence which parodies love as flippancy parodies merriment. Next to the Blessed Sacrament itself, your neighbor is the holiest object presented to your senses. If he is your Christian neighbour, he is holy in almost the same way, for in him also Christ vere latitat, the glorifier and the glorified, Glory Himself, is truly hidden.