The liberal camp includes many thinkers I admire, and it has produced some of the more eloquent reflections on biotechnology’s implications for human affairs. But at least in the United States, the liberal effort to (as the Goodman of 1980 put it) “monitor” and “debate” and “control” the development of reproductive technologies has been extraordinarily ineffectual. From embryo experimentation to selective reduction to the eugenic uses of abortion, liberals always promise to draw lines and then never actually manage to draw them. Like Dr. Evans, they find reasons to embrace each new technological leap while promising to resist the next one — and then time passes, science marches on, and they find reasons why the next moral compromise, too, must be accepted for the greater good, or at least tolerated in the name of privacy and choice. You can always count on them to worry, often perceptively, about hypothetical evils, potential slips down the bioethical slope. But they’re either ineffectual or accommodating once an evil actually arrives.

Tomorrow, they always say — tomorrow, we’ll draw the line. But tomorrow never comes.

— Ross Douthat