I have been rereading Nietzsche's On the Genealogy of Morals. The prose is moving, inasmuch as one is moved by prose (I am but very little), but the content seems to my eye poorly reasoned (relying heavily on rhetorical flourish and single examples instead of methodical dissection and consideration of possibilities) and highly anachronistic from a modern perspective (complete with what today seems like particularly odd racial/ethnic/cultural viewpoints and a generous helping of historical inaccuracies).
Given this, I simply don't know what to do with this as a body of work, aside from note its intriguing place in history and its influence on thinkers of the time. The Critique of Pure Reason, in contrast, sets out a clearly defined and carefully reasoned thesis and therefore has contributed a permanent and in some sense timeless approach to morality and knowledge and such (even though one may argue with the reasoning or assumptions in numerous places).
Thus the question is (quoted for emphasis):
Is there some consensus of what the lasting value* is of On the Genealogy of Morals? Where would one find a compelling argument in favor of this value? Or is it perhaps only comprehensible in the context of other of Nietzsche's works (which I have at best skimmed), which together contain a view of lasting value? Or is it best viewed not as part of the collected knowledge of the field of philosophy, but rather as an interesting but ultimately transient part of its history?
To expand a little further: my usual sources for these sorts of questions have not been as helpful as usual. Wikipedia summarizes the content, but has only a very sparse coverage of critiques and modern perspective. IEP covers Nietzsche in great depth, but barely mentions On the Genealogy of Morals. SEP has an article on Nietzsche's moral and political philosophy, but the discussion is so mixed between On the Genealogy of Morals and other works that I can scarcely recognize any of the Genealogy in it; this nonetheless makes me wonder whether when viewed as a whole the works of Nietzsche paint a clearer picture of which G.M. is an essential part. And in every case, the focus is more on what he said than was it true; a discussion or defense of the latter is what I am most sorely lacking because so often, even when attempting to take Nietzsche's use of terms like "aristocrat" into account, his claims seem so often blatantly wrong that I wonder why G.M. continues to be viewed with more than historical interest. Or maybe it is merely historical interest. Or maybe most everyone agrees that it was in large part blatantly wrong, but it was blatantly wrong in such interestingly different ways than intuitively obvious yet actually wrong views that came before (and keep arising) that it has value as sort of a buffer, a counter-narrative that undermines a tempting yet misleading view of human morality.
*To clarify what I mean about lasting value, since this is apparently not an intuitively obvious term: philosophy as a field attempts to study things the way they are or should be, both as the primary field for several types of inquiry (morality, comprehensibility of the world, etc) and as meta-analysis for others (philosophy of mathematics and science, for instance). Philosophy is not merely an expression of human creativity or artistry (we have art and literature and music and so on for that). Therefore, to study philosophy, one needs to be familiar with what philosophy studies, and what progress has been made in that study: what are the most natural questions to ask, and what compelling answers have been given? Are there counters to those answers, and so on? In this vein, for a philosophical work to have lasting value, it must either demonstrate something that is (at least approximately) true and relevant--either for the first time or as one of the best explanations yet, or it must raise a question or open up a new branch of philosophy (or close off an old one) and do so in one of the most compelling and clear ways that has been devised. It is not of lasting value, in the sense I mean, if it was merely part of a historical trend of moving in a new direction. For example, Giotto's painting Christ before Caiaphas was part of a trend towards improved perspective in paintings, but it is of no "lasting value" for accuracy in painting because the method used is wrong--wrong enough so that one shouldn't duplicate it--and because it is not terribly clear from looking at the painting what it was that he was doing.