I have some sympathy with the view that philosophy is a waste of time, though I hope it isn’t. I really fear, however, that normative informal logic might be –though I cannot the basic self-referential problem that judging it to be a waste of time requires using it, therefore, etc.
There is a discussion on the Leiter Reports about the worthlessness of philosophy, as argued in Peter Unger’s recent book (and discussed in this interview at 3QuarksDaily). Some, in the comments on LR, allege Unger’s thesis is self-refuting (along the lines mentioned above). Someone responded–anonymously–as follows:
So far, it seems most people are either attacking Unger personally for having a cushy philosophy job while saying philosophy sucks or are resorting to cheap tricks like: If philosophy is empty and his argument is a philosophical one, then that’s empty too, so there.
This accurately describes some of the comments, but the anonymous author here ought to know that such arguments are not ipso facto fallacious or irrelevant (I’m guessing this is what the author means by “cheap tricks”) because they’re ad hominem. We’ve discussed this here. Unger’s failure to apply his thesis too himself may be a sign that he doesn’t find his view credible. More importantly, the self-referential failure of Unger’s view (if this is accurate), is not really a cheap trick, but rather the entire stupid problem. Philosophy, in particular epistemology and its various applied fields, studies the question as to what makes for justified belief that something is worthless. A worthwhile endeavor.