Would an 'independent' NHS create a worse provider monopoly than British Leyland or set it lose from the targetitis of Whitehall? Who would hold the reins of scrutiny - regulators, Parliament or local councils? Where are the models - the BBC, Scandinavia, Oregon or New Zealand? Is independence even a coherent goal or a continuum to be judged against different functions and organisations?
This week's roundtable discussion (see pages 22-25) about the independence debate brings together some of most insightful commentators on the health service and perfectly shows the breadth of issues at stake. What does emerge is a consensus that removing politicians from day to day operations is welcome, already happening but also not simple to define - there is no clear line between operational decisions and value judgements which should rightly be supported by a political mandate.
It is also clear that a failure to address weak commissioning would be a major and dangerous impediment to effective independence. Could the government make commissioners strong, legally independent and locally accountable without another reorganisation? It is difficult to see how local commissioners could retain an effective relationship with a central commissioning board, a body that would look a lot stronger on paper than in practice.
As HSJcolumnist Simon Stevens points out in the debate, if you remove the catalytic effect of political leverage, you will have to replace it with something equally powerful. It's not yet clear what would have the necessary energy.
This year will be an important one for a debate that is not new but is becoming more pressing. Bullish Conservative talk in the autumn about introducing an 'independence bill' early in the new year had gone quiet of late but earlier this week David Cameron promised publication later in the year. It remains to be seen whether it will find itself at the top of Gordon Brown's to-do list in the summer.