Over at Commonweal, John Schwenkler takes R.R. Reno’s side in yesterday’s debate over libertarianism:

As Reno points out, theWSJ’s blinkered focus on the role of tax policy in encouraging economic growth assumes a social policy of its own, one according to which GDP is the sole or main measure of a society’s health. Too, the WSJ’s claim that a pro-family tax policy “merely rewards taxpayers who have children over those who don’t” overlooks the role of tax policy in encouraging people to have children, and assumes once again that this — as opposed to growing the economy, of course! — isn’t something that tax policy should be in the business of doing. In short, theWSJ editors are guilty of exactly the charge they lay before Santorum: they pretend to be putting forward a “strictly” economic platform, which actually embeds a social policy of its own.

And he poses a further question:

One thing that might be added to this is that certain social policies, tax-related and otherwise, can positively thwart proper human flourishing, as e.g. when we drive up the cost of housing and education, and make it prohibitively difficult to live on a single income, thus keeping families small and driving their members apart. What are some other aspects of our “essential human nature” that require social policies for their proper cultivation? I can think of quite a few.

While I agree with Robert Miller that there’s nothing necessarily relativistic in declining to use the tax code for social policy, he seems to be singing into the wind. Tax deductions are just much easier to argue for than transfer payments, and whatever general advantages there are to the latter are swamped by their political impracticality.

In the Journal’s op-ed, I see an argument that purports to be neutral and principled being wielded very deliberately and specifically against a thing the Journal doesn’t care for. Encouraging investment through reduced tax rates on capital gains? Sure. Encouraging family formation through a tax deduction? Not so much.