I CAN’T have been the only 40-something who was excited to see Pink Floyd on stage at Live 8. David Gilmour (59) now has the face of a retired bank manager, but Roger Waters (61) still looks rock-credible. Dave had the advantage, at least, of being able to rest his guitar on his paunch between riffs.

As teenagers, we loved the way Pink Floyd attacked power in all its forms: political authority, the power of money, the social control exercised by education. I went to a school where we were still caned for misdemeanours; so “Hey! Teacher! Leave those kids alone!” really spoke to us.

It is because power is dangerous — whether in the hands of a teacher or a prime minister — that we must find ways to subject all power-structures to criticism. But in our new issue-driven politics we don’t ask enough questions about the general dynamics of power. The past decade has seen government get more powerful and less accountable. Since 1997, for example, there have been 43 Bills that strengthen powers of law and order. And now identity cards are on their way. We ought to be much more interested than we are.

Which is why I believe we need to bring Karl Marx back from the philosophical graveyard. You won’t find single issues in Marx’s writings, because he was concerned with fundamental structures. Looking at the mass of “suffering humanity”, Marx urged a “reckless critique of all that exists, reckless in the sense that the critique is neither afraid of its own results nor of conflicting with the powers that be” (Jahrbücher, 1843).

Marx is not well-understood, partly because Marxism offered us a distorted cartoon of his views. And partly because his really interesting writings of the mid-1840s were not published until 1932, when the image of Karl Marx was fixed in the public mind.

The Paris Manuscripts (1844) show us an existentialist Marx who argues that all political economies tend to alienate us from our true human nature. Work becomes slavery; nature becomes a commodity; money becomes a fetish. Our happiness lies in overcoming our self-alienation and building a society where we “exchange love for love, trust for trust”.

This new society will be the fulfilment of our deepest human identity: “the human being in the whole wealth of its being, with manifold sensitivity as its constant reality”. Work will be balanced with leisure, and the individual with the community. It’s almost Benedictine.

Overcoming alienation is no simple task. Those with power have a vested interest in maintaining the status quo. Single-issue politics, effective as it often is, does not address the question who controls the system as a whole. This is why we must subject our political and cultural regimes to ideological criticism.

Of course, much of Marx’s thought, particularly his economic theory, has been discredited. But we need to put that to one side, because Marx could see something we are losing sight of: that the key issue in any society is power.

The Revd Dr Hugh Rayment-Pickard is Area Dean of Kensington