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 focus of environmental ethics should indeed be on the virtues and how these inform our relationship to natural environments.

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.

To recognize that you are radically free, in Sartre's sense, but then to live as if you weren't, is to live in bad faith, in denial of what you know to be true. And that's not something anyone can sensibly want to do.

The aim of dis-incumbence is a hubristic one, for it requires confidence in the ability of men and women to live in the belief that nothing they do can, in the end, be justified by anything. That's a belief that it is easy to proclaim in seminar rooms or pubs, but not one that people could actually live with.

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.

I think it's true that for existentialist thinkers, appreciation of what we are - free, makers of meaning, 'issues' for ourselves, and so on - is at the same time a recognition of how we should try to live.