Caroline Lucas has today issued a striking public call for a new politics of unity among 'progressives' - among those, that is, who seek at minimum to rein in the excesses of neoliberal 'business as usual', Tory-style.

With less than six months to go before the most wide-open General Election of our time, a true insurgent party is on the rise, and – despite what the media tell you – it’s not the one you are thinking of.

Spring 2007: the high-water mark of self-confidence for economic neo-liberalism. In March, both Henry Paulson and Ben Bernanke publicly stated that they saw no danger of recession, and that the subprime fiasco had been ‘contained’. As late as mid-May, with the sub-prime crisis in full throe, still Bernanke felt able to say this: Importantly, we see no serious broader spillover to banks or thrift institutions from the problems in the subprime market. In July, Paulson claimed: This is far and away the strongest global economy I’ve seen in my business lifetime; and on August 1st, I see the underlying economy as being very healthy. Neo-liberalism remained a movement triumphal around the world. No bunch of poverty-stricken mortgage-defaulters – who could conveniently be blamed for the little local difficulty – were going to derail this ideology.

George Monbiot is correct in his praise of Thomas Piketty's proposal for a wealth tax to counteract the insane levels of inequality now generated in our world, and in pointing out that only the Green party is prepared to back this obvious idea. However, we should be careful not to let Piketty's helpful intervention in the debate blind us to the severe limits of his own stance in political economy.

We live at a point in history at which the demand for individual freedom has never been stronger — or more potentially dangerous. For this demand — the product of good things, such as the refusal to submit to arbitrary tyranny characteristic of ‘the Enlightenment’, and of bad things, such as the rise of consumerism at the expense of solidarity and sociability — threatens to make it impossible to organise a sane, collective democratic response to the immense challenges now facing us as peoples and as a species. ”How dare you interfere with my ‘right’ to burn coal / to drive / to fly; how dare you interfere with my business’s ‘right’ to pollute?” The form of such sentiments would have seemed plain bizarre, almost everywhere in the world, until a few centuries ago; and to uncaptive minds (and un-neo-liberalised societies) still does. But it is a sentiment that can seem close to ‘common sense’ in more and more of the world: even though it threatens to cut off at the knees action to prevent existential threats to our collective survival, let alone our flourishing.

What would a post-growth world look like? Some would argue that it is not difficult to imagine a world without growth, as many countries are already living in it.

Japan stagnated for a decade and its economy has been left hollowed-out. Much of Europe is in negative or near-zero growth in the wake of the global economic crisis, and in none of these countries can a lack of growth be viewed as a good thing.

We see before our eyes the human cost of economic systems that are dependent on constant growth to function. We currently rely on growth for all kinds of purposes. As a substitute for the redistribution of wealth, for example - so long as everyone is getting richer, why worry if some are getting much richer than others?