The piece yesterday, Just how serious is the economic crisis?, included the thoughts of John Milbank. He is a rare, because genuinely challenging, voice in public debate right now. What I didn't get in yesterday, though, is that he finds much support in Catholic social teaching - and that's where I start to feel nervous.

For example, Milbank rightly critiques the firm, that operational unit in capitalism that by way of contractual, defensive and self-interested relationships, undermines trust - the quality that is so necessary for a flourishing economy. But doesn't the Catholic Church act quite like a firm too, with its strict clarity on who's in, and who's out; with its defense mechanisms against the infidels? Is not target culture a bit like confession culture? Is not computer-says-no a bit like catechism-says-no?

Then, for liberals who might want to take on board some of the critique of liberalism - that it places too much emphasis on arbitrary choice and solipsistic individualism - the problem with the Catholic church is that it is just so retrogressive. Catholic social teaching really needs to get its act sorted out when it comes to women, gays and sex, though that ain't going to happen any time soon, which means its insights will remain marginal.

And then, there's that air of arrogance, coming from an institution that essentially believes it has the answer, that its task is no more or less than presenting the Truth afresh in every generation. What happened to the conversation that was Christianity, when no-one believed they had a mainline to absolute good, because only God is good? We need a discussion about the common good, an effort to discern a variety of responses that are emergent, not a monopoly that Opec-like is imposed.