I'm very sceptical about the prospects for 'big' environmental causes - 'saving the planet', halving the world's population, ending the exploitation of animals, and so on - but a person can ask him- or herself how he or she personally may exercise compassion or humility towards animals, vegetal life and so on.

The dis-incumbenced stance is the one people should cultivate, we are told, once they recognize that there is no world beyond the human world. They will, indeed must, have their beliefs and values, but they will recognize that these 'lean upon' - and are answerable to - nothing other than human commitments and purposes. The only fidelity, Rorty remarked, can be to our own conventions.

Chuang Tzu and Heidegger both emphasise the virtue of 'spontaneity' - a sort of mindful responsiveness to things as they are. It's this notion, I suspect, that is the best bet for helping to make some sense of talk about harmony or unity with nature.

Between nature and music there seems to be an elective affinity: they fit together, and when they do experiences of an ineffable kind are generated.

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'.

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.

In all great civilizations, garden discourses have belonged to larger discourses about beauty, the good life, the relation of humankind to nature, and so on.