Those who have followed Barrie Kosky's theatre over the past two decades should already know that the man is a rampant sensualist. This quality is often obscured - or perhaps evaded - by popular perceptions that he is (a) an arch intellectual or (b) a show off, both of which are assumed to be somehow above sensual delight, or even opposed to it. On the contrary, flamboyance and intellectual passion are the dress of sensual vitality. Underneath the eye-catching raiment, the divine and profane meet in the naked body. And there the self is overwhelmed, even annihilated, by the stimuli of touch and taste, smell and hearing and sight, in a present moment which is so fully inhabited that it becomes all we will ever know of eternity. Ecstasy.

Those who refuse to hide from the intensities hidden within ordinary human experience tend to become mystics or poets. Or, perhaps, a certain kind of theatre director, theatre being an artform where the pragmatic material world and the finite human body collide with the ineradicable human impulse towards the divine, or whatever it is that wrenches us out of our quotidian selves into a wider possibility of being. (We all have our own names for it; I call it beauty). And perhaps it's no wonder that people prefer to think of Kosky as a clever dick. It's easier than admitting the painful, exhilarating worlds that exist at the edges of one's own skin. As the poet said, human beings cannot bear very much reality.

For Kosky, ecstasy begins with his grandmother's chicken soup. "My Polish grandmother," he says, remembering himself as a seven year old boy, "made a chicken soup like no other chicken soup....[It] was the Caravaggio of soups. The Rainer Maria Rilke of soups. The Arturo Benedetti Michelangeli of soups..." It happens when he is watching HR Pufnstuf or losing himself among the mink coats in his father's fur warehouse in Richmond or in the symphonic smells of the boys' changing rooms at school. And, three decades later, he experiences the same rapture in Wagner's Tristan und Isolde. Such ecstasy, as the mystics knew, is not expressible in language, which seeks to imprison the fluid moment in a fixed, linear past:

In the end, this music can only be experienced. Interpretation fails. Words are useless. Recordings do it no justice. You have to see the melody emerge from deep within the singer's body. To hear the melody being born out of the singer's mouth. To touch the melody as it travels through space. To smell the melody as it floats around you. To taste the melody as it submerges into your own body. Echoing. Vibrating. Ecstatic.

For all the impossibilities of language, Kosky's essay On Ecstasy, released this month by Melbourne University Press, is a seductive, exhilarating and illuminating read. It will tell you a lot about Wagner and Mahler and the ecstatic possibilities of theatre but, like ecstasy itself, it's not really biddable to interpretation. Kosky writes like he talks, with the same excessive gestures, the same self-mockery, the same passion, the same sense, dare I say it, of show business. I totally enjoyed it. The best thing to do is to read it for yourself. Second best, you can get to the Melbourne Writers Festival at the uncivilised hour of 10am on August 24, and hear the man himself in conversation with Julian Meyrick. Better still, do both.