For me, the existentialists are important critics of 'absolutist' claims, and Heidegger and Merleau-Ponty are, at least in their later writings, also exponents of a doctrine of mystery: Being or the 'well-spring' of everything is, for Heidegger, ineffable, just as what Merleau-Ponty called 'Flesh' is for him.

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.

There are really three players: 'absolutists', for whom it is possible to describe reality as it anyway is; 'constructivists' or 'humanists', for whom there is nothing beyond a world that is relative to human interests and conceptual schemes; and 'ineffabilists', like myself, for whom any describable world indeed exists 'only in relation to man', as Heidegger put it, but for whom, as well, there is an ineffable realm 'beyond the human'.

In the doctrine of the world and humankind as 'will to power and nothing else', Heidegger identified not an antidote to nihilism, but the completion of it. For what can be more destructive of truth and value than the doctrine that these are simply the impositions on the world of human exercises of power?

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.

The main objection to the 'scientistic' claim that physics describes the world as it is in itself is that you 'can't weed out' the human contribution. That is, the scientific image of the world, like any other, is indelibly shaped by our interests, practices and prejudices.

The writing I have in mind and sometimes indulge in myself is concerned, not with plants, mountains or birds as items of scientific description, but with experiences of nature that impinge upon our moods and emotions, enrich our imagination and reveries, and shape our sense of how we stand in relation to the environing world. In a broad sense of the term, this kind of writing is an exercise in phenomenology, an attempt to render the significance that birds, plants or whatever have for us.