Oh shit I might be postmodern
Obviously. But pretending otherwise for a moment, the final sentence of Eagleton's chapter on Morality is:
A socialist society co-operates for certain material purposes, just like any other; but it also regards human solidarity as an estimable end in itself. As such, it is beyond the comprehension of a good deal of contemporary theory, for which solidarity means tepid consensus or baleful conformism rather than a source of value and fulfilment.
I cannot speak for contemporary cultural theory but I see the cultural consensus and solidarity of, for example, football and the X-Factor as tepid, and enthusiasm for espadrilles and UKIP as baleful. That's why I don't have a TV, because I don't want anything to do with idiots. I don't want solidarity with the English, I want to be apart from them. I'm a contractor because being a permanent employee makes my stomach tighten, and my life contract.
But I am a socialist and a member of the Labour party[^1]. I want the safety net of socialism because I can't be sure what will happen to me, or how well my children will do, or their children. I want everyone to be more-or-less ok, no matter what they can achieve. I want the less well off to be better off, and to get the respect that every human deserves. This is just empathy and pity. It's got nothing to do with narratives of solidarity, and my brand of socialism, my reason for wanting the policies that I do, is just as real and valid as Eagleton's. And this socialism doesn't have a problem with the postmodern.
[^1] I joined because of David Cameron's 2013 Tory party conference speech, where he announced he was going to take away housing benefit from the under-25s, a move about nothing more than class, aging wealth, and politik.