You could hardly hope for a better illustration of our mixed feelings about oil.

Just a few days ago, on Earth Day, we ran a survey asking which industry sector you'd like to vanish off the planet - for the sake of the planet. By a very long way, oil came first.

But then drivers in Scotland started to fill up on petrol in expectation of a fuel shortage, and my colleague Robin Pagnamenta noted that without ample oil supplies we would starve.

So do we hate oil, or crave it? Or, like addicts who recognise the harm done to them by heroin or alcohol, do we both love and hate oil all at once?

The ecologist and writer Alastair McIntosh has written in his stunning book Soil and Soul that some things that seem harmless in themselves can, at a certain remove or huge scale, become terrifyingly harmful. Quoting John Steinbeck, he observes that the banks that foreclosed loans and caused such suffering in the Great Depression were staffed with people who, almost without exception, hated what the bank was doing. But they did it anyway, because the "emergent properties" of the banking system called on them to do so. McIntosh suggests that these emergent properties are fundamentally unavoidable in any human system, and that they might possibly be what previous generations had in mind when they talked of "the devil" - an anthropomorphic embodiment of what today we choose to regard as mere abstracts.

Certainly, it's possibly to see the "devil" in oil. It's undoubtedly useful and pleasure-giving stuff - as indeed are heroin, so I understand, and alcohol - but we allow these things to take over our lives at great peril.

Whether we're "possessed" by devils or merely addicted, we must all take a share of the responsibility. Which is not to say that we should feel guilty - which does nobody any good - but we should think hard about the implications of what we do and try to change, little by little. After all, people have lived for all but the tiniest part of human history without any oil at all.

Which brings me back to the idea that we are all going to starve. Well, it's true that current agricultural practice relies on fossil fuels to a vast degree (ten calories from oil for each calorie on the plate!). But it's also true that we can all grow foods in window boxes, on local scrubland, and in our gardens without using any of those artificial aids. If you aren't doing so already, why not? Even one lettuce makes a (small) difference.

Nor do you need even to buy plastic (eg, oil based) pots for the seedlings. These ones, in an improvised cold-frame in my garden, are made of newspaper and slowly rot in the ground.

My friend Richard Reynolds, of the Guerilla Gardeners, has a book coming out about the great tradition of growing things where there was nothing before. I'm looking forward to reading it - and only hope that Richard has added to his previous writing, about decorative planting, something substantial about how we can grow food on common land, as did Richard's 17th century forebears, the Diggers.