In his Review of Fair Pay in the public sector, Will Hutton enters territory usually reserved for philosophers. If we are going to talk about fair pay, he tells us, we must begin by identifying what fairness is. His own answer is that fairness is a matter of what he calls due desert, meaning that people should be paid in proportion to the contribution they make to their organisation’s success. He says an employee’s contribution cannot, however, be assessed simply at face value: it must exclude the effects of free riding as well as of brute luck, good or bad. Only by stripping these things away are we able to judge what someone’s true contribution has been.

Hutton (who is interviewed in the May issue of PM) is not alone in thinking that how people fare in life should be independent of the luck they experience: our attitude to people who accidentally fall on hard times is a lot more forgiving than it is to those who lose their life savings on a bet. Moreover, Hutton’s ideas have no shortage of supporters in academic circles among the community of thinkers called luck egalitarians. They believe that a fair distribution of goods between people is one that is untainted by their good or bad fortune.

But the idea that fairness has something to do with luck has its critics as well as its devotees. And even its most ardent supporters accept there are no easy answers to the question of what in our lives should and should not count as luck to begin with. Hutton has his own stab at this issue, citing gender and ethnicity as examples of human characteristics that are down to luck and therefore illegitimate bases for occupational reward or penalty.

Luck, however, is an elastic notion. Each time we attribute one feature of our lives to it, we find ourselves asking: “Why stop there?” It is by this process of argument that many philosophers have moved from the everyday examples cited by Hutton to the idea that luck - and certainly unequal luck - pervades all quarters of our lives. Gender and ethnicity are just the start of the story. Surely, the argument runs, it is also a matter of luck that some are better educated than others or more naturally gifted - or that they happen to find themselves living and working in a particularly favourable (or unfavourable) economic climate.

If, in the name of discounting the effects of luck, we should be as suspicious of rewarding people on the basis of education, talent, and favourable circumstances as we are of rewarding them on the basis of gender and ethnicity, the implications for hiring, firing, paying, and promoting are profound indeed.

The familiar idea that people should be paid according to how well they do their job is an important one: it instructs us to judge people at face value according to how they perform on the job, not according to their background or upbringing. When applied in good faith, it attacks many of the prejudices that so dismay Hutton and the rest of us. But it does not attack the effects of fortune in their totality, in the manner of a grand philosophical position such as luck egalitarianism.

If we are to benefit from the liberating possibilities present within the idea of taking people at face value, we have to recognise this same idea allows people to enjoy rewards at work that are traceable to good luck (in terms of their education and natural talent) and suffer penalties that are traceable to bad luck (such as that, for whatever reason, they are no longer fit to do their job properly).

In case the latter seems morally insensitive, just ask yourself how you would feel about being operated on by a surgeon who had kept her job because, though she had lost much of the sensation in her fingers, it was through no fault of her own. Whether someone has enjoyed good or bad luck at the workplace is certainly relevant to how she should be treated by her employer and the compensation she might be eligible for. But it is not relevant all the way down. The workplace is not a court of law. It is neither feasible nor desirable for employers to become preoccupied with questions of credit and fault as though they were in the business of assessing the moral worthiness of employees.

In his search for philosophical credibility, Hutton has ended up offering convolution, not clarity. He has tried to pack too many moral principles into the relatively narrow confines of the workplace and the result is messy and confusing. To say that fair pay has something to do with desert and luck is to exit one area of controversy only to enter another. If we agreed on what desert required of us or how far the realm of luck extended we would probably not be arguing about the fairness of public sector pay in the first place. It is precisely because we do not agree about these things that, Hutton or no Hutton, the debate will continue.