What I mean by pluralistic values is embodied by the fact that these particular reformers are at odds with one another: The climate-change people believe we'll be worse off environmentally if the "increase the birth rate" people succeed, especially if they succeed in wealthy nations where per capita carbon output is relatively high. In neither his original column nor his follow-up post does Douthat address the environmental objection to a public policy that deliberately aims for constant population growth, except in an aside about what radical environmentalists might prefer.

What about regular environmentalists, whether of the climate change, water shortage, or "we're running out of fish" variety? I am agnostic about the ideal number of people on the planet, but it doesn't seem obviously implausible that "a bit fewer than today" is the "right" number. Nor does it seem implausible that declaring any number "right" is to impose an answer to a question where various deeply contested sets of values are at play, and a laissez faire approach is therefore best. Reflecting on a world that gave us China's "one-child" policy and that is likely to have abortion on demand forever after, does Douthat really want to make the birth rate a matter of government targeting? My instinct is to maintain the norm that these sorts of decisions are best made by individuals acting in an uncoordinated fashion to live as they see fit, or else who knows what reproductive reforms some latter-day Michael Bloomberg might try to impose.

Finally, this whole conversation is missing a crucial piece of context. Says Douthat in that follow-up post:



...if children are not the only good in human life, they do seem like a fairly important one, no? Maybe even, dare one say, an essential one, at least in some quantity, if the pursuit of the wider array of human goods is to continue beyond our own life cycle? Or to put it another way, if we have moral obligations to future, as-yet-unborn generations, as almost everyone seems to agree, surely those duties have to include some obligation for somebody to bring those generations into existence in the first place -- to imitate the sacrifices that our parents made, and give another generation the chances that we've had?



In theory that sounds reasonable enough, but it's also written as if we face a population decline so serious that future generations are being deprived of a chance to exist. As a reality check, let's look at some United Nations population projections:

billions more people than it had in 1970 or 1980 or 1990. Now let's take

In other words, even modest population decline starting around 2040 would leave the world withmore people than it had in 1970 or 1980 or 1990. Now let's take a somewhat longer view





That isn't to say that even more humans might not be a good thing, that a shrinking population wouldn't present Douthat is right that having kids, "at least in some quantity," is an important good "if the pursuit of the wider array of human goods is to continue beyond our own life cycle." What I can't understand, especially in the context of history, is why Douthat thinks a modest decline from current population levels, for all the challenges it might pose, jeopardizes the continued pursuit of human good. Barring a pandemic, a meteor, or a catastrophic war (all possibilities!) there will be many billions more human beings in 2100 and 2200 than there have been for 99 percent of human history. Why does, say, 5 billion people fall short of the "some quantity" he had in mind?That isn't to say that even more humans might not be a good thing, that a shrinking population wouldn't present a lot of thorny challenges , or that Douthat is wrong to prefer a world with bigger families. In fact, I think some of Douthat's critics are being unfair to him by presuming malign motives, and I think his eagerness to non-coercively extend life to more human beings is a well-intentioned project, whether or not it is wise. What seems unsupportable to me are the assertions that folks who take a different view are both decadent and putting continued human progress in jeopardy, especially when environmental factors make it possible that a failure to "pause" before solving the carbon problem will retard human flourishing over a long time horizon.