My previous postings on this topic have tended to concentrate on responses that have been made, and thought justified, in response to works of Jacques Derrida. For some reason, his "style" is thought to be irritating by a number of people and this irritation has been rationalised by means of allegations of obscurity and, with this, an allegation of "wilful" attempts to mislead by means of such alleged obscurity. Previous postings gave short shrift to this reaction.
A thoughtful posting over at Pea Soup pursues this question from a slightly different angle, though, once again, taking off from a response to the writings of Derrida. As is pointed out here the canon of philosophical writings includes many, not least Kant, who are writers whose work is by no means evidently "clear" and yet who we take to be worth the effort required to try to work out the sense of the texts they wrote. This does instantly show that if clarity is a mere synonym for "accessibility" then there would be a serious problem with defending quite a considerable number of works in the history of philosophy. The fact that this attitude is generally not adopted does suggest that standards of what should be understood to be examples of "clarity" in philosophy can also be very varied. Is Aristotle, for example, more or less clear than Kant? Even if "clarity" is taken as a synonym for "accessibility" then there would be varied answers here depending on which works were focused on and, even within the works, which passages and stretches of argument. Also, given that the reputations of philosophers rise and fall at different points it would seem that the basis of appreciation is not clearly tied to standards of "clarity".
A second point made in the piece referred to above is that the irritation some feel when reading Derrida is one that rises from what the author calls: "the posturing, the pretense, the thin layer of bullshit that covers such exercises of coded insider-talk". Whilst this may well indicate sentiments felt the notion of the writing in question itself containing something that clearly corresponds to this attitude is disavowed by the author of the posting. Since the writing in question is effectively "innocent" of such "crimes" then what is it that lies behind such responses? After all, some of us might feel that the prose of, say, Quine, is rather more rebarbative than that of Derrida and that it certainly addresses an "in-crowd" through its own mode of "insider talk".
The sense of "insider talk" might well get at the problem better as it suggests a feeling of exclusion on behalf of certain readers when confronted by certain types of writing. Again, that exclusion can hit different readers differently since I, for one, feel much more excluded from the writings of Quine than those of Derrida. So this sense of exclusion might well have something to do with a certain kind of expectation when confronted with philosophical prose, an expectation that is at issue in the demand for "clarity". What this expectation would refer to is a model of writing that has been picked up from certain types of philosophical writing that the reader has grown habituated to such that when a different type of style is presented the search for comprehension of the piece gets disappointed. In this case, however, the problem surely lies with the reader for importing an expected standard that might well be the right one for getting published in journals of academic philosophy and for being taken seriously at conferences held in certain places with certain types of people attending. However, surely that reflects the generalisation of a certain model without accompanying argument for the basis of this model and simply assumes the greater transparency of this model based on the experience of a selective group? In which case the standard of "clarity" has itself, as I suggested in previous postings, been significantly left under-determined.