The demands of the economy, and more recently those of political correctness and the diktat against ever offending anyone, are not conducive to a classroom or university seminar climate in which genuinely free and critical reflection on how to live prospers.

It's one thing to assent to propositions like 'The way of things is ineffable', and quite another to internalise what it is being gestured at by such propositions, to get a sense or feel for mystery. For me, at least, it is in and through ways of engaging with nature that this sense is intimated. These ways include being in the garden.

Does the unmistakeable intent of Versailles to proclaim dominion over nature destroy its aesthetic appeal, as Schopenhauer thought? Does the greenness of the lawn lose its allure when we learn how much water, sorely needed elsewhere, it uses? And historical shifts in garden taste - from formal, 'French' gardens to 'Capability' Brown's landscapes, for instance, or from the elaborate gardens of imperial Kyoto to Zen 'dry' gardens - register important changes in philosophical or religious attitudes.

Like Nietzsche, Heidegger also gave up on the prospect that schools and universities would nurture the kind of reflective openness to the way of things that, certainly by the 1940s, he identified with authentic thinking. The authentic person is not the Promethean, iron-willed figure that pops up in Nietzsche, but someone more like the Daoist sages whom Heidegger admired.

To recognize that you are radically free, in Sartre's sense, but then to live as if you weren't, is to live in bad faith, in denial of what you know to be true. And that's not something anyone can sensibly want to do.

I think that Asian versions of 'ineffabilism' have an advantage over the best-known Western ones, like Schopenhauer's. They are free from the dualistic image of the world of experience as the joint product of mind and reality.

My 'heroes' are those - like Chuang Tzu and Heidegger - who recognize that the world of experience is a human world, but recognize too that there is a 'way' or a 'source' to which our lives are answerable.