In a comment on an earlier post Chris Wales confesses that he's not too keen on the state trying to preserve a measure of equality in society. Rather,if I've understood him correctively, he is in favour of unfettered (and not necessarily equal?) opportunity.
This is an interesting question and deserves a full post (and perhaps several) rather than an additional comment.
Most modern states, as Chris acknowledges, accept that there should be some sort of welfare safety net to prevent too severe destitution, and we have had such as system, with varying degrees of generosity, in this country since the Elizabethan Poor Law. It was Jo Grimond, in an article, I think in the Observer the early 1960s, who alerted my to the concept that the democratic state also had a duty to prevent some people becoming too rich, because, as I recall, they endangered democracy. Lord Aschcroft, Rupert Murdoch and Silvio Berlusconi are prime examples of how right he was (as in so many other things.)
A few rich individuals perhaps add a bit of glamour to society (the Dockers provided it in the 1950s, though, as far as I know, they paid their taxes, and at a pretty high rate) but a substantial section of society who become so rich that they are detached from the rest of us, live in gated communities and cease to be affected by our common concerns endanger the cohesiveness of our society, just as does the detachment of the bottom 20% into their separate Toynbee "caravan." We would be so much happier as a society if we really were "all in this together." This explains so many people's nostalgia for the war years, when the rich as well as the poor had a chance of being bombed out of their homes or called up for service.
It is a sad reflection on the current spirit of the Labour Party that, although Ed Milliband seems keen to retain the 50% higher tax rate as a matter of principle other senior members aren't so sure. When Neil Kinnock was their leader his book choice on Desert Island Discs was R H Tawney's "Equality", which contains this wonderful passage:
"It is possible that intelligent tadpoles reconcile themselves to the inconvenience of their position by reflecting that, though most of them will live and die as tadpoles, and nothing more, the more fortunate of the species will one day shed their tales , distend their mouths and stomachs, hop nimbly on to dry land, and croak addresses to their former friends on the virtues by means of which tadpoles of character and capacity can rise to be frogs" (Allen and Unwin edition,1931, page 142)
As Tawney clearly saw, equality of opportunity is merely equality of opportunity to become unequal. To become unequal and not pay your dues to the society that enabled you to do so is even less acceptable.