Edward Feser has touched on the matter of haughtiness in philosophy  and how it may overwhelm rational commitment and truthfulness, such that there is a refusal to admit simple or obvious mistakes; and he has reminded me of something that J.R. Lucas wrote:
“When I started philosophy, Logical Positivism was very much in vogue, and my tutor tried hard to get me to believe the Verification Principle. So I asked him whether it was a tautology, perhaps showing some new meaning being given to ‘proposition’, or ‘meaningful’, so that only some selected instances could be accorded the favour of being thus described. He said No. Was the Verification Principle, then, an empirical proposition, discovered by careful research in which lots and lots of propositions had been examined, and none found to be meaningful except those that were analytic or empirical. He admitted, albeit a trifle reluctantly, that no such research had been carried out. In that case, I concluded triumphantly, the Verification Principle, if it were true, was itself meaningless, hoist by its own petard. He did not think it a very good argument, and told me to try harder to believe.” 
Herewith a little sketch of an argument:
I. It goes without saying that I am a very clever and careful analytical philosopher.
II. Very clever and careful analytical philosophers, such as I, do not make or accept obvious mistakes.
III. It goes without saying that I do not make or accept obvious mistakes.
IV. Anyone who does not recognise the obvious truth of (III), which logically follows from the obvious truths of (I) and (II), is making an obvious mistake.
V. Anyone who claims that I have made or accepted an obvious mistake is (a) making an obvious mistake and is (b) not a very clever or careful analytical philosopher. [From II, III, and IV.]
VI. Very clever and careful analytical philosophers, such as I, ought to dismiss as unworthy of consideration the obviously-mistaken claims of not very clever or careful analytical philosophers.
VII. I ought to dismiss as unworthy of consideration any claim made by anyone that I have made or accepted an obvious mistake. [From V and VI.]
 Edward Feser, “Rosenberg Responds to his Critics”, Edward Feser (weblog), 10th December 2009; last paragraph. Therein also: “in contemporary academic philosophy, what is grounds for failing an undergraduate paper can be Festschrift material for a professional.”
 J.R. Lucas, “A Simple Exposition of Gödel’s Theorem”, A Talk at King’s College, London, October 1996, reproduced online at the website of J.R. Lucas.