An abiding and central concern of philosophy and religion alike is the fear that the world is alien to human beings, that nature is, in Hegel's words, 'out and out other' to 'spirit'. It's easy enough to see how 'constructivist' or 'humanist' conceptions are efforts to dispel this fear.

Things only 'show up' for us as they do, as Heidegger would put, in and through practical engagements with the world that enable objects to have significance and salience - as hammers, pots, trees or whatever.

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.

While I am happy to make the occasional foray into educational philosophy - writing, for example, of the difficulty in the contemporary context for a teacher to be 'truthful' - it is more the personal conduct of a life than social institutions that I am concerned to examine.

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.

I rather shared Nietzsche's conception of the kind of individual that an ideal education should be cultivating. 'Authenticity' is not Nietzsche's term, but as used by some existentialists, it nicely captures what Nietzsche admired - the resolve of an individual person to forge his or her own 'table of values', to be emancipated from strait-jacketing conventions, traditions, and ideologies. As embodied in the 'Overman', authenticity is the antidote to 'bad' nihilism.

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.