On the train home from today's forum, I opened Giorgio Agamben's book of essays, Means Without End: Notes on Politics, to this serendipitous passage:

'Primo Levi has shown... that there is today a "shame of being human", a shame that in some way or another has tainted every human being. This was - and still is - the shame of the camps, the shame of the fact that what should not have happened did happen. And it is shame of this type, as has been rightly pointed out, that we feel today when faced with too great a vulgarity of thought, when watching certain tv shows, when confronted with the faces of their hosts and with the self-assured smiles of those "experts" who jovially lend their qualifications to the political game of the media. Those who have felt this silent shame of being human have also severed within themselves any link with the political power in which they live. Such a shame feeds their thoughts and constitutes the beginning of a revolution and of an exodus of which it is barely possible to see the end.'

It was almost startling, since it articulated something of the complexity of what I was feeling at the time. There I was, being an "expert", in a context in which my position behind the microphone and the attendance of an audience made a constituency of authority. And within that constituency, with the authority, however spurious or legitimate, conferred on us as panellists, we spoke about the act of theatre criticism.

I have no wish to impugn my fellow panellists, who are neither dishonest nor unintelligent, however I might disagree with them on occasion. Nor do I wish to exculpate myself. My sense of disturbance was much more subtle than any easy j'accuse, and difficult to track because it was also familiar, like one's own body odour. For whatever reason, a miasma of depression rose gradually inside me as the discussion progressed. There was nothing overtly wrong with the talk; it was unexceptionable, at worst boring. It was well-intended. It was agreeable; at times even jovial. I am not sure what the eighty or so good people who attended might have learned: that theatre critics like going to the theatre, that they have varying opinions on the point and value of what they are doing, that they have varying relationships to those they criticise and their employers, that they consider themselves informed commentators.

So what was this inarticulate scream, this "silent shame", which gradually oppressed me? For there was nothing to put my finger on, nothing overtly objectionable: nothing, you might think, to remind me of anything so extreme as a concentration camp. The connection, I suppose, is in the expression "the vulgarity of thought". The vulgarity does not lie necessarily with the individual critics speaking, but in the tacit contexts which constrain discussion, so that it may never reach any pitch of disturbance. The vulgarity twists around, I suspect, the very DNA of our culture. Is it partly that very Australian fear of intellectual seriousness, which makes its very expression a matter of defensive anxiety, as if to be too serious were a breach of propriety? Is it that our very passions are muted, as if they were swaddled in cotton wool? Or is it that any designation as "expert", as part of a group of "experts", taints one inevitably with complacency?

I am not quite sure what I am attempting to say. All I know is that if I am honest with myself, I felt a kind of shame, sitting there behind the microphone. I have sat on more than a few panels in my time, and it is always an experience fraught with dubiety; but the panels on theatre criticism have always had this particular flavour, which today I was able to identify. It seemed to me that, for all its display of culture, what we did today had nothing to do with art. It is perhaps not going too far to say that I felt, in some way that is not, in fact, easily identifiable, that it seemed to negate the very possibility of art itself.

This begs the question of what I think art might be. I can't answer that question; I can think of no general definition which is remotely adequate. It is not enough to deny that art is a commodity; of course it is a commodity. To claim that art is a created thing with a quality of excess that escapes commodification feels closer to what I mean. And yet we seem incapable of speaking of art except in terms of its value as a commodity - as a consumable item which may be "rated" (three stars or five?), in all its forms from a basic "entertainment" to the kind of product which confers less tangible benefits, such as social or intellectual status. Not only does this seem to miss the point; it obscures it almost beyond rescue. For there is a point, ungraspable as it may seem, which may hold value in its very ungraspability.

I realise I am very close to saying that art is the same as the sublime. Given I can't abstract art from its material nature - theatre simply wouldn't exist without the sweaty temporality of the human bodies which enact it - I clearly can't quite mean that. This materiality seems to me in fact art's redemptive vulgarity, a certain crudity which is very different from that vulgarity of thought Agamben refers to. Perhaps, within this sublime vulgarity, I find a kind of hope. The problem is that it's not hope for anything: just hope itself, ridiculous and naked. And it is, like all ridiculous and naked things, an embarrassment, a fracture of ease, which may admit then another possibility - joy? grief? play? life? Maybe it was the lack of this very fracture which made me feel so infinitely and yet so indefinitely hopeless. For lack of unease, I was ashamed; I felt I had participated in the imprisoning of something I think of, not as an expression of freedom, but as freedom itself.

I certainly couldn't have said anything like this at the event today. I could not have even thought it, and nor would it have been "appropriate". After all, we were only talking about theatre reviewing.