Yesterday I read G. K. Chesterton’s Heretics for the first time and came across a passage on progress:

The case of the general talk of “progress” is, indeed, an extreme one. As enunciated today, “progress” is simply a comparative of which we have not settled the superlative. We meet every ideal of religion, patriotism, beauty, or brute pleasure with the alternative ideal of progress—that is to say, we meet every proposal of getting something that we know about, with an alternative proposal of getting a great deal more of nobody knows what. Progress, properly understood, has, indeed, a most dignified and legitimate meaning. But as used in opposition to precise moral ideals, it is ludicrous. So far from it being the truth that the ideal of progress is to be set against that of ethical or religious finality, the reverse is the truth.

Nobody has any business to use the word “progress” unless he has a definite creed and a cast-iron code of morals. Nobody can be progressive without being doctrinal; I might almost say that nobody can be progressive without being infallible — at any rate, without believing in some infallibility. For progress by its very name indicates a direction; and the moment we are in the least doubtful about the direction, we become in the same degree doubtful about the progress. . . . I do not, therefore, say that the word “progress” is unmeaning; I say it is unmeaning without the previous definition of a moral doctrine, and that it can only be applied to groups of persons who hold that doctrine in common. Progress is not an illegitimate word, but it is logically evident that it is illegitimate for us. It is a sacred word, a word which could only rightly be used by rigid believers and in the ages of faith.

Last week Ryan Anderson wrote about a symposium at Princeton devoted to the question of whether ending early human life is wrong. He rightly called attention to the position of Princeton’s Elizabeth Harman, who argued that, “Things have moral status throughout their existence, just in case there’s any time in their existence at which they are conscious.” That is, a fetus has moral status even before it reaches consciousness if, and only if, it lives long enough to reach consciousness sometime later. Hence, if a fetus is aborted before it reaches consciousness, then it in fact never will reach consciousness and so never has moral status. Killing such a fetus is thus morally permissible. As Anderson puts it, Harman’s position occasioned much head scratching at the symposium.

I think I see, however, why this putative principle seems so puzzling. We need moral principles, first and foremost, to guide conduct. They tell us what we may do and what we may not do in certain cases. If the question is whether we may kill a certain human fetus, we want moral principles that will help us answer that question. Harman’s principle, however, comes to this: We may kill the fetus if, and only if, we actually do kill the fetus (thus ensuring that it is never conscious). If we were to try to use this principle to determine whether we should kill some particular fetus, we would thus first have to know whether, in fact, we actually will kill it. But we will kill it only if we first decide we may kill. Hence, to use Harman’s principle to decide whether we may kill a certain fetus, we would first have to know whether we may kill that fetus. This makes the principle useless for guiding conduct and thus no genuine moral principle at all.