Commenters on a previous post say I'm spreading defeatism. Britmouse says I'm a professional sceptic. This raises a queer paradox. As a Marxist and extremist, shouldn't I be the utopian dreamer whilst centrists are the pragmatic realists?

No. In fact, the opposite is the case. My Marxism and my scepticism are the same thing. I fear that capitalism is inconsistent with full employment, except under conditions that don't now exist, and capitalist ideology excludes from the Overton window radical policies such as a seriously redistributive tax and benefit system, a genuine jobs guarantee or worker ownership. As a result, prospects for improving workers' living standards are limited.

Of course, this is not to say they are non-existent; a sensible fiscal policy would do some good. My suspicion, though, is that there are tight constraints on what centre-left politics can achieve.

This, though, seems to be precisely what the non-Marxist left reject.I fear there's a danger that they are exaggerating the benefits of Ballsian fiscal policy, corporate tax compliance, a living wage or job subsidies.

In this sense, it's the centre-left who are the utopian dreamers, and we Marxists who are the realists.

This shouldn't be surprising. Political activists, and especially career politicians, are selected for the optimism bias; you don't go to all those dull meetings unless you think (conventional) politics can achieve a lot.

And it's not just mainstream politicians who are the dreamers whilst I'm the sceptic. Stock-pickers who think they can beat the market and CEOs who think they can successfully control ther fate of huge organizations are just like centre-left politicians, exaggerating what they can achieve in the face of powerful and complex market forces.

Now, I might be doing the soft left a disservice here. Perhaps there's a glass half-full/half empty issue, with me stressing the emptiness and the soft left the fullness. But if this is so, I wish they'd be more candid about the fact that poverty, unemployment and inequality (of power as well as wealth) will remain even after they have enacted their favoured policies.

As it is, the question "what can politics achieve in a capitalist economy?" is rarely posed, let alone answered, by the centre-left. And until it is, they are likely to remain Isobel Crawley-type figures - perhaps doing a little good, but not challenging basic socio-economic inequalities, and leaving poverty and their own privilege largely unchanged.