Jonah Goldberg says it's why he's pro-life. To which comes the rather obvious reply:
Why is it seemingly only in the context of abortion that Jonah believes uncertainty militates in the direction of governmental activism on behalf of those whose lives could be at risk?
The counter-examples cited include:
bans on smoking in public places, stricter gun control, motorcycle-helmet laws, and even spending on social programs like S-CHIP.
The equally obvious rejoinder is that non-fetal humans can look after themselves. Life is indeed a principle worth defending, when there's doubt as to whether a recognizable human person exists at all. Better safe than murderous, right? But the sheer fragility of early pregnancy, and the ubiquity of zygote death in the womb suggests that nature's standards are somewhat more lax than today's conservatives' when it comes to life in the first trimester (it's all there in The Conservative Soul, if you're interested in a doubt-based conservatism on the question of abortion). What's lacking among today's conservatives on the question is a sense of prudence and restraint that stems from doubt. And a general refusal to allow government to boss human beings around in their most intimate and difficult decisions. Aquinas was more persuasive. And he knew far less.