For many years, the pragmatist-philosopher Richard Rorty has been telling us that the world outside the mind — or outside a community of minds — is unknowable. Unlike his less sophisticated brethren, however, he has never claimed to know so; rather he has always maintained a “liberal irony” towards the view. That he remains committed to so bold a view only through this liberal irony, however, speaks not only of a very odd mind, but also of the poverty of the arguments formed in favour of that view, arguments so poor that they cannot persuade even the philosopher of pragmatism who proposes them. A typical example:
[O]nce you have said that all our awareness is under a description, and that descriptions are functions of social needs, then ‘nature’ and ‘reality’ can only be names of something unknowable. 
Here is the argument in a clearer syllogistic form:
All awareness is under a description,
All descriptions are functions of social needs,
All descriptions (of “nature” and “reality”) are names of something unknowable.
The conclusion does not follow. Furthermore, the premises are far from established; for nowhere is there to be found any compelling evidence for the view that all awareness is under a description or that all descriptions are functions of social needs. Indeed, for Rorty and his kind, there could be no evidence, and therefore they are forced to feed themselves on a diet of fanciful theories:
To say that everything is a social construct is to say that our linguistic practices are so bound up with our other social practices that our descriptions of nature, as well as ourselves, will always be a function of our social needs.
Naturally, in the slough of his liberal irony, Professor Rorty himself wouldn’t claim to know that all awareness is under a description or that all descriptions are functions of social needs. Such would presuppose what he sets out to deny. Thus, he sets his argument upon premises in whose truth he claims not to believe, in order to establish by a non sequitur a conclusion in whose truth he claims not to believe, in favour of a view in which he is far from being compelled to believe by the impress of his everyday life. One might well wonder why he bothers. Professor Rorty, however, is rather keen to “keep the conversation going”.  He is the old fishwife of the philosophical world.
 Richard Rorty, “A World without Substances or Essences”, in Philosophy and Social Hope (London: Penguin Books, 1999), p.49.
 Ibid., p.48.
 Richard Rorty, Philosophy and the Mirror of Nature (Princeton: Princeton University Press, 1979), p. 377.