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.

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.

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.

As for the meaning of gardens, particular gardens may have, of course, all sorts of different meanings - emotive, historical, emblematic, religious, commemorative, and so on. But I think that good gardens all signify or exemplify an important truth about the relationship of culture and nature - their inseparability.

I started my professional life as a philosopher of language and for several years took the orthodox line that meaning is an essentially linguistic phenomenon. Whether as a result of simply listening to everyday talk about meaning, or reading books of anthropology, sociology and art history, it dawned on me that there is nothing at all privileged or central about linguistic meaning.

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.

What impressed me about Plato and Sartre was their conviction that we should live our lives in the light of big truths about reality and human existence.