The fight for free space-for wilderness and for public space-must be accompanied by a fight for free time to spend wandering in that space. Otherwise the individual imagination will be bulldozed over for the chain-store outlets of consumer appetite, true-crime titillations, and celebrity crises.

In her novel Regeneration, Pat Barker writes of a doctor who 'knew only too well how often the early stages of change or cure may mimic deterioration. Cut a chrysalis open, and you will find a rotting caterpillar. What you will never find is that mythical creature, half caterpillar, half butterfly, a fit emblem of the human soul, for those whose cast of mind leads them to seek such emblems. No, the process of transformation consists almost entirely of decay.

There are those who receive as birthright an adequate or at least unquestioned sense of self and those who set out to reinvent themselves, for survival or for satisfaction, and travel far. Some people inherit values and practices as a house they inhabit; some of us have to burn down that house, find our own ground, build from scratch, even as a psychological metamorphosis.

You write your books. You scatter your seeds. Rats might eat them, or they might rot. In California, some seeds lie dormant for decades because they only germinate after fire, and sometimes the burned landscape blooms most lavishly.

Growing up north of San Francisco, I immersed myself in the local landscape and in books about Native Americans, cowboys, and pioneers that seemed to ground me in it, but to pursue culture in those days meant being spun around until dizzy and then pushed east.

There is so much information that our ability to focus on any piece of it is interrupted by other information, so that we bathe in information but hardly absorb or analyse it. Data are interrupted by other data before we've thought about the first round, and contemplating three streams of data at once may be a way to think about none of them.

Walking shares with making and working that crucial element of engagement of the body and the mind with the world, of knowing the world through the body and the body through the world.