- What's the source for this comment?
Rorty infamously claimed (in so many words) that there is no essential difference between philosophy and litcrit.
- Has any other philosophers argued this?
If you're looking for where Rorty says this or might be taken to imply it, then Contingency, Irony, and Solidarity (1989), is the best place to start. I base this advice on the following review :
There is another crucial dualism in these essays. For Rorty, there are two kinds of philosophical methods or procedures: the arguments of common sense and the descriptions of intellectuals. This dualism defines the second dominant feature of Rorty's stories. Rorty rejects common sense and traditional argumentation, and instead proceeds by literary criticism, description, and redescription - by sweeping stories about the histories of philosophy and literature. Rorty seems to view common sense as hopelessly narrow and naive, and he characterizes philosophy by-argument as hopelessly tied to foundationalist epistemologies, transcendental metaphysics, and supposed final, essential vocabularies.
By contrast, he advocates philosophy-by-redescription, and awards it the "ironist" seal of approval. Ironist philosophers, Rorty explains, are "never quite able to take themselves seriously because they are always aware that the terms in which they describe themselves are subject to change, always aware of the contingency and fragility of their final vocabularies, and thus of their selves" (74 75). However, it does seem that ironist philosophers take one another very seriously. In fact, as Rorty describes them, they seem downright clubby: "So our doubts about our own characters or our own culture can be resolved or assuaged only by enlarging our acquaintance. The easiest way of doing that is to read books, and so ironists spend more of their time placing books than in placing real life people" (80). Ironists, Rorty continues, take literary critics as their moral advisers because these critics have large ranges of acquaintances - they "have been around." This may be so, but it is instructive to note that at least in one important and distressing respect, ironists and traditional metaphysicians are alike. Although they differ about the reality of contingency, both fear contingency. For Rorty, contingency is dangerous, threatening, humiliating; it suggests that life is futile. As a result: "Literary criticism does for ironists what the search for universal moral principles is supposed to do for metaphysicians" (80). (John J. Stuhr, 'Contingency, Irony, and Solidarity by Richard Rorty', The Personalist Forum, Vol. 5, No. 2, Humanism (Fall 1989), pp. 149-152 : 150.)
R. Rorty, Contingency, Irony, and Solidarity. Cambridge: Cambridge University Press, 1989. ISBN 978-0521353816.
Rorty does not make the claim that there is no essential difference between Philosophy and Literary Criticism/Theory. Rorty acknowledges that some (most?) current philosophers believe that there are fundamental differences between philosophy and literary criticism. He calls such philosophers metaphysicians, and contrasts them with people like himself, whom he calls ironists/pragmatists.
What Rorty does claim is that for ironists/pragmatists, literary criticism has superseded the style of philosophy preferred by metaphysicians: The rise of literary criticism to preeminence within the high culture of the democracies - its gradual and only semiconscious assumption of the cultural role once claimed (successively) by religion, science, and philosophy - has paralleled the rise in the proportion of ironists to metaphysicians among the intellectuals. Contingency, Irony, and Solidarity (CIS), p.82. Literary criticism is not the same as traditional metaphysical philosophy (or even modern analytic philosophy), it is a new and better way of thinking about our world.
Consequently, philosophy and science are viewed by ironists/pragmatists as simply literary genres, alongside novels and plays:
But, ironically and dialectically enough, what Hegel actually did, by founding an ironist tradition within philosophy, was help de-cognitivize, de-metaphysize philosophy. He helped turn it into a literary genre. CIS, p.79
I can put these two points together by saying that whereas nineteenth century idealism wanted to substitute one sort of science (philosophy) for another (natural science) as the center of culture, twentieth century textualism wants to place literature in the center, and to treat both science and philosophy as, at best, literary genres. The rest of my paper will be an attempt to refine this crude formula and to make it plausible. Consequences of Pragmatism (CoP), p.141.
The strong textualist [roughly equivalent to an ironist, NG] simply asks himself the same question about a text which the engineer or the physicist asks himself about a puzzling physical object: how shall I describe this in order to get it to do what I want? Occasionally a great physicist or a great [literary] critic comes along and gives us a new vocabulary which enables us to do a lot of new and marvelous things. Then we may exclaim that we have now found out the true nature of matter, or poetry, or whatever. But Hegel's ghost, embodied in Kuhn's romantic philosophy of science or Bloom's philosophy of romantic poetry, reminds us that vocabularies are as mortal as men. The pragmatist reminds us that a new and useful vocabulary is just that, not a sudden unmediated vision of things or texts as they are. CoP, p.153