A few weeks ago, some of my philosopher friends were sharing this Chronicle of Higher Education article, "Is Philosophy Obsolete?", the tag-line of which reads, "No. It helps make us coherent to ourselves, and that's a never-ending project."
I don't think "seeking coherence" can be an adequate way of defending, or doing, philosophy.
First, there appear to be conclusive reasons to think that coherence per se is not truth-conducive (see sections 7&8 here). A set of beliefs can be as coherent as you like--but, for all that, they can be totally out of touch with the truth. This is a longstanding objection to coherentist theories of epistemic justification, and it seems to be a definitive one.
Second, while some might be willing to bite this bullet--suggesting that philosophy needn't be about getting at truth (I've heard a few people suggest this!)--I don't think that's a bullet we should want to bite. Making false views more coherent can be a very dangerous endeavor. Among other things, it can make false and harmful theories or belief-sets seem more plausible to those who already endorse them, as well as to others. To take just a few examples, consider Sir Robert Filmer's defense of the divine right of kings in his 1680 book, Patriarcha. Or consider young-earth Creationism or the views of the Flat-Earth Society. Or, of course, consider racism and white-supremacy. These doctrines can be rendered increasingly coherent, and indeed, their proponents have spun all kinds of coherent defenses of them--defenses which their proponents think constitute evidence for the view in question. But this, clearly, is a very dangerous thing to do. We should want to avoid approaches to inquiry that can lend an "air of legitimacy" to views that are false.
Finally, notice that coherence in one obvious sense lends itself to a kind of status quo bias. If our task as philosophers is to simply make our beliefs more coherent, we must begin with whatever beliefs we have--which is plausibly what led Filmer and those of his ilk to defend the divine right of kings. That doctrine fit with many status quo beliefs at the time, so of course it seemed defensible on coherentist grounds. Similarly, people resisted Copernicus' heliocentric theory of the solar system because it contradicted "commonsense" at the time. People resisted (and some still resist) the theory of evolution on such grounds. And yes, many physicists and philosophers initially greeted Einstein's theory of relativity not with open arms, but rather condemnation as obviously inconsistent with the "a priori fact" that space and time (obviously!) must be absolute.
For these reasons, I don't think philosophy or science should be in the business of rendering "commonsense" coherent. They should be in the business of discovering the truth--for, as we see in history, the truth often defies commonsense (or, at least, what people take to be commonsense at a given time). But how? What does it take for philosophy to be truth-conducive? And, are we currently using truth-conducive methods? Like a seemingly growing number of philosophers, I have a variety of concerns, some of which I would like to share here and explore in this post and several to come.