Gardening is an excellent example of a practice to which, as Alasdair MacIntyre puts it, certain virtues are 'internal'. Good gardening requires a certain goodness on the part of the gardener: care, humility, patience, and respect, for example.

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.

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 Overman will himself be a nihilist in the (good) sense of rejecting any metaphysical or religious grounding for truth and value, but instead of curling up in despair, or simply going along with the crowd like the 'passive' nihilist, he will recognize himself as the sole source of truths and values to live by.

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.

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.

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.