Has there been, or can there ever be, progress in philosophy? Not just any kind of progress, mind you (clearly, there is chronological and dialectical progress), but progress in philosophical knowledge. What that is and my proposed answer to the question will have to wait until a further post (or until I have more settled views on the matter). For now I want to comment on the following remark by Dr. Vallicella:
That there is no consensus in philosophy among competent practitioners is a widely-accepted fact, one that cannot be reasonably disputed. I challenge anyone to give me a clear example of a philosophical problem that has been solved to the satisfaction of all competent practioners [sic].
I may not be a competent practitioner of philosophy, but is Vallicella saying that if, say, Robert Adams were to dispute the claim that there is no consensus in philosophy among competent practitioners, he would be ipso facto unreasonable? Suppose Adams reasoned thusly: “What do you mean by ‘widely-accepted,’ and how do you distinguish that from ‘consensus’? If they’re synonymous, would there not be a consensus in philosophy among competent practitioners that there is no consensus in philosophy?”
Presumably this not the kind consensus in philosophy that Vallicella has in mind, for the consensus has to be on a “philosophical problem,” and the question of whether there is consensus in philosophy is not a philosophical one. (I don’t see any difference between a philosophical problem and a philosophical question; all philosophical questions are philosophical problems and vice versa.) So if “Is there consensus in philosophy?” is not a philosophical question, what kind of question is it? An empirical one? Is it a matter of just polling competent practitioners of philosophy?
The terms ‘consensus’ and ‘philosophy,’ of course, require philosophical analysis, and admit of differing conceptions. So the question also admits different answers. But let’s stipulate that there is a consensus on what ‘consensus’ means, which we’ll say is “near-unanimous agreement among diverse competent individuals and groups who have a shared understanding of the question/problem.” Even so, there is no consensus on what the relevant sense of ‘philosophy’ is, and so there is no consensus answer about whether there is or can be consensus in it. To get an answer, we’d have to fix on some understanding of ‘philosophy’ and take a poll. Until then, the answer is underdetermined.
So we have a dilemma: either the question is a philosophical one, in which case there is consensus on a philosophical question after all (contra Vallicella), or the question reduces to an empirical one, in which case there likely is not a consensus on the question (contra Vallicella).