There is something myopic and stunted in focussing only on the meaning of words and sentences. And this myopia is especially unfortunate when combined with a rather abstract view of a language as a set of elements and rules for combining these. For the result is to divorce enquiry into meaning from attention to the way words - and gestures, facial expressions, rituals and so on - are embedded in practices, in what Wittgenstein called 'the stream of life'.

There is no reason at all to think that creatures with very different purposes and concerns would arrive at the scientific image, and no reason at all to accuse such creatures of getting the world wrong - a point that both Chuang Tzu and Nietzsche make when comparing human and animal perspectives.

It is hubris, claim the critics of 'absolutism', to suppose that we could ever even approximate to a true description of how the world anyway is. It is bad faith or 'bullshit', respond 'absolutists', to suppose - as the rhetoric of postmodernism implies - that we could seriously live and act with the thought that truth and value are simply our own projections. An attractive feature of 'ineffabilism', as I see it, is that it evades these accusations.

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.

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.

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.

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.