Via the Peej, K.M. Parsons offers an op-ed defense of public funding for philosophers. Philosophy provides critical thinking, you see, and if citizens were unable to think critically, they'd be nothing but a mob of indoctrinated partisans, you see.
Let's assume that professor Parsons is correct and that the discipline of philosophy does indeed grant students durable, robust critical thinking skills. Let's assume further that the marginal philosopher (extend this to all of the social sciences and humanities if you like: political science, sociology, economics, take your pick) contributes meaningfully to students' ability to question and revise their unexamined beliefs. Assume, if you will, that the exchange between professors and students is euvoluntary.
Even if all of that is true, even if "philosophy is valuable" isn't just a naked assertion, even if the Republic Herself were at stake, a more convincing argument would include at least some mention of how peaceful exchange is insufficient to the task of making sure the next (and by "next" I don't mean Aristotle or Hume or even Sandel or Searle; I mean the third-string just-barely-made-tenure assistant professor at an unranked department) philosopher earns employment. A complete argument, in other words, includes at least some mention of public goods, in the rigorous sense, in that I benefit from your ability to think critically, or that anyone at all benefits from Peppy Not-Quite-Good-Enough-For-Tenure Professor's latest desk rejection. If public funds were supporting the next Summa Theologica, you'd probably be able to get away with hand-waving market failure rebuttals. But that's not what's being argued.
I tend to agree that education is among the new commanding heights. It would be churlish of me to assume that this didn't imply that a great deal of rack and ruin in the editorial pages were sure to follow. But if you must defend your discipline against reasonable objections to outrageous relative price increases, do yourself and your readers a favor and write as if you respected their intelligence.