The title The Conversation of Humanity, which Stephen Mulhall uses for his latest book (University of Virginia Press, 2007), might strike some as odd. Does humanity just have one conversation? What about the Tower of Babel, to say nothing of the so-called ‘information explosion’ and the thousands if not millions of television channels, blogs, web-sites, message boards, chat rooms and plain old-fashioned books, magazines and newspapers (more than ever, despite the e-revolution)? At least to some minds, including to Mulhall himself, most of this produces nothing so much as an incessant and enervating background to any real attempts to think and speak. So does Mulhall think that beneath all this babble, and all the earlier babble of earlier ages, there is one canonical conversation going on, which might be called the conversation?

In his book Mulhall focuses particularly on Wittgenstein, Heidegger and Stanley Cavell. In his discussion of Wittgenstein he gives a partial answer to his use of the singular definite article in connection with conversation(s). He takes issue with the interpretation of Wittgenstein which would have that philosopher as postulating distinct and self-contained language games. For Mulhall, as for Rush Rhees, the motley of language does go to make a unity in which it is ultimately impossible and unavailing to insulate bits off from each other, for in using one area of discourse we always bring in or rely on many others; and this unity, which is the unity of a conversation, also extends to ultimate distinctions between the factual and the evaluative. Furthermore, language, being rooted in living (which is itself a whole), is always, potentially anyway, about something. Against Thrasymachean sophistry, an evil view in Mulhall's opinion, in which language is only about persuasion and not really about anything true or real, for Mulhall as for Rhees, living makes sense, and so therefore does language and philosophy.

Well, maybe not all language. For when he discusses Heidegger Mulhall skilfully analyses Heidegger's distinctions between das Man (man in the mass) and Dasein (the true individual able to respond to being-itself), and between Gerede (mere chatter) and authentic speech. We have the potential to be individuals, elaborating our own take on things, adding genuinely to the conversation of mankind; but most of us most of the time prefer to lapse into the common thoughtlessness, represented by das Man and Gerede (see the last sentence of our first paragraph). In genuine conversation the real otherness of the other brings out my own individuality (what Heidegger calls conscience); I and my interlocutor respond to something genuine within ourselves and also to something beyond ourselves, being itself as revealed by me and us. Gadamer is introduced at this point as taking the reading of the great books of the past as being ideally a conversation of this sort, but Oakeshott and Rorty are castigated (mildly in the first case and more severely in the second) for taking a fundamentally aesthetic, if not sophistical view of the conversations; that they are games, not really about anything, not having any point outside themselves. We imagine, though, that Rorty would have been aware of the thought that if living makes sense, then language makes sense, but would simply have denied that ‘sense’ has to be interpreted in the way Mulhall does.

No matter; for Mulhall authentic conversation is a form of genuine self-discovery and of world-discovery, and as such leads to a quest for perfecting of self and world. Following Cavell, this quest will have political implications, and also, of course, personal ones. Mulhall quotes with approval Heidegger's Nietzsche inspired aphorism that man is a passage, a transition, and also St Paul's idea (in 2 Corinthians) that we ourselves are epistles of Christ, being written not with ink, but with the spirit of the living God. Perfectionism for Mulhall is not, it goes without saying, ever a finished matter. But in so far as what is revealed about ourselves and about the world is seen as worthwhile, it will involve an element of praise, of gratitude for what we elicit. No doubt some would see this praise in Rilkean terms, as religio intransitiva; just praise that the world is, and that we can appreciate these things, but thanks to no creating agency. Mulhall's take on this, by contrast, is definitely a transitive one; for him thinking is ultimately thanking (as for Heidegger denken will be danken), and his book ends with an illuminating analysis of Augustine's framing of his Confessions as a prayer, a hymn of praise to the God he has always been seeking, albeit unknowingly, in all his activity.

Whether one agrees with Mulhall or not, his book is both penetrating and, considering the authors he is discussing, extraordinarily clear. We have, though, already intimated that Rorty might not have been too impressed with Mulhall's riposte to his views, and maybe Thrasymachus will live to fight another day. So a question remains as to the truth and ultimate acceptability of what he says. Do we have, in the end, to accept that decisions on such fundamental matters might be, in a deep sense, a matter of taste?

A conversation which did, after a fashion, actually take place was that between Russell and Bradley on idealism generally and on such matters as relations, identity, predicates and necessity in particular. A general view is that the winner (Russell) showed Bradley to be wrong on pretty well all counts, which is why Russell won. In The Russell/Bradley Dispute and its Significance for Twentieth-Century Philosophy (Palgrave, 2007), Stewart Candlish shows this view to be pretty well wrong on all counts, if by ‘won’ we mean ‘provided rationally compelling refutations of Bradley's views’. That does not, of course, mean to say that Bradley's style was helpful to his cause or that his views may not in various ways have been unpalatable as well as ultimately unfashionable. But (maybe against Bradley's own thought) being unpalatable is a relational term, and does not in any case throw light on the truth.

In his concluding chapter Candlish approvingly quotes David Lewis and Peter Hylton as asserting that at a deep level philosophical theories are never refuted conclusively, and less approvingly Geoffrey Warnock's remark that systems such as Bradley's are more vulnerable to ennui than to disproof. Maybe, though, ennui might have something to do with it; that an important element of philosophical decision is a sense of how we want to live, together with developing a sense of what that presupposes. If this were so, it would bring philosophy back closer to its historical origins as a turning of the soul, that is as much valuational as intellectual, than may be apparent in contemporary philosophical practice, rather as in its own way Mulhall's book does so strikingly.