Breaking the Law -- DeMorgan's Law:

Lots of court opinions are derided as illogical, but there's one that's illogical in a pretty technical way. I was just teaching it today, and thought I'd blog briefly about it.

The opinion is Justice Brennan's opinion, joined by Justices Marshall and Stevens, in Texas Monthly v. Bullock (1989). In that case, the Court struck down a Texas sales tax exemption for religious books and magazines; Justice Brennan's opinion concluded the law violated the Establishment Clause, because it impermissibly discriminated in favor of religion.

But the Court had before then upheld some religion-specific exemptions, so Justice Brennan had to explain when such exemptions were permissible and when they weren't. Here is what he said:

[W]hen government directs a subsidy exclusively to religious organizations that is not required by the Free Exercise Clause and that [(1)] either burdens nonbeneficiaries markedly or [(2)] cannot reasonably be seen as removing a significant state-imposed deterrent to the free exercise of religion, as Texas has done, it [violates the Establishment Clause.

(We can set aside the "is not required by the Free Exercise Clause" phrase because of later developments.)

Yet that's what he said in the text; here's what he said in footnote 9:

[W]e in no way suggest that all benefits conferred exclusively upon religious groups or upon individuals on account of their religious beliefs are forbidden by the Establishment Clause unless they are mandated by the Free Exercise Clause. [Case discussion omitted.-EV] All of these [constitutionally permissible religion-specific exemptions], however, involve legislative exemptions that [(1)] did not, or would not, impose substantial burdens on nonbeneficiaries while allowing others to act according to their religious beliefs, or [(2)] that were designed to alleviate government intrusions that might significantly deter adherents of a particular faith from conduct protected by the Free Exercise Clause.

So the text essentially says: Unconstitutional if (1) substantial burden on nonbeneficiaries or (2) no removal of state-imposed deterrent to religious exercise.

The footnote essentially says: Constitutional if (1) no substantial burden on nonbeneficiaries or (2) removal of state-imposed deterrent to religious exercise.

Sounds congruent, because not (A or not B) sounds equivalent to not A or B. But of course the two aren't equivalent; DeMorgan's Law says not (A or not B) is equivalent to not A and B.

The opinion is thus essentially internally inconsistent. It's theoretically possible to reconcile the two provisions, for instance by saying that the test in the text is limited to subsidies (including tax exemptions) and the test in the footnote is more general, or by reading the elements of each test subtly differently. But I doubt this makes sense; I think the Justices were trying to make the tests cover the same territory, use the same elements, and be functionally identical. Unfortunately, they broke DeMorgan's Law, and are being punished by having their opinion reduced to incoherence.