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.

Does the unmistakeable intent of Versailles to proclaim dominion over nature destroy its aesthetic appeal, as Schopenhauer thought? Does the greenness of the lawn lose its allure when we learn how much water, sorely needed elsewhere, it uses? And historical shifts in garden taste - from formal, 'French' gardens to 'Capability' Brown's landscapes, for instance, or from the elaborate gardens of imperial Kyoto to Zen 'dry' gardens - register important changes in philosophical or religious attitudes.

How people make gardens is bound to reflect a way of experiencing the natural world, while at the same time this experience of nature is bound to reflect a culture - ways of painting nature, for example, or representing nature in literature, or of course making gardens.

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.

For many years, questions about the meaning of life were dismissed as senseless. We were told that life, not being a word or sentence or anything language-like, can't intelligibly be said to have meaning. An encouraging development in the last couple of decades is a return by philosophers to addressing - as nearly all people do at some time or another - the question of life's meaning.

It is indeed impossible to describe reality 'in itself', but that does not mean that our lives are answerable to nothing but our own conventions and commitments. They are answerable to a way of things that transcends the reach of our conceptual schemes.

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.