How many jobs does one rich boss need

You wouldn't sniff publicly at the pay slip, at any rate. When average earnings in Scotland are hovering at around £21,000, you wouldn't want to give the wrong impression. You certainly wouldn't want it to get around that you had allowed yourself to be put forwa rd for a part-time job paying – this is not a typographical error – £4583 a day. It looks bad.

It looks much worse if you are meanwhile being paid taxpayers' money to run a "sponsored non-departmental public body" dedicated to the common good called Scottish Enterprise (SE). That counts – and this is not a matter of opinion – as a full-time job, a big job, an all-consuming £200,000 a year job. Common sense would tell you to be sensitive to the fact.

Then again, common sense would also tell you that accepting £55,000 for 12 days work a year in the private sector in London while publicly-funded colleagues cover for your absence back home is a very bad idea indeed. An inability to grasp why this would anger people just compounds the problem. It causes your judgement to be called into question.

Dr Lena Wilson, chief executive of SE, is widely regarded as a paragon. There's no reason to doubt it. She has risen high and fast in the economic-development game while maintaining a range of interests in education, the arts, sport and voluntary organisations. No glass ceiling, it is always worth observing, has contained her. So while going through "seven or eight" interviews for that £55,000 non-exec job with the Intertek Group, didn't she once wonder: "How will this look?"

The strictly accurate answer seems to be: up to a point. Wilson apparently realised, for example, that she would have to make time for a monthly commute "in addition", as SE puts it, "to her contracted hours". Her solution has been to resign from her voluntary position on the board of The Prince's Scottish Youth Business Trust for the sake of moonlighting with a FTSE 100 company. Somehow I don't think it quite solves the problem.

That can be defined as follows. Wilson is the first chief executive of SE to take up a private-sector directorship while remaining in public employment. That's a conflict of interest in and of itself. Though she will, of course, recuse herself if Intertek's affairs impinge on the day job, the stratagem will only make a bad situation worse. How do you attempt to lobby for Scotland's economic development while avoiding any mention of one of Britain's biggest companies?

Even the minor details in this affair are astonishing. Wilson will be gone from the office for a day each and every month. Others will be left to hold the fort, no matter how many hours the £200,000 a year chief executive thereafter puts in. SE doesn't deny it. So who thinks this is a good idea?

Salmond, for one, if his defence of Wilson last Thursday was anything to go by. Questioned by Willie Rennie, the Liberal Democrat leader, the First Minister pointed out irritably that the SE chief executive had already "relinquished" a bonus to which she was contractually entitled. Leave aside the weird idea of an entitlement to a bonus. Wilson is adding roughly 27% to her income, with Government approval, while continuing to receive a very large salary as a public servant. That's what you call a bonus.

Her SE chairman, Crawford Gillies, was another who couldn't see the problem. "This is excellent news for Lena, for Scottish Enterprise and for Scotland," he announced grandly. By this account the appointment "sends a strong signal about the calibre of public sector leaders we have in Scotland". As though describing a deluxe work-experience placement, Gillies then offered "my sincere congratulations on what is a remarkable achievement". Of potential damage and actual damage, to an organisation or to an idea, not a word.

They see no harm in it. Wilson, clearly, had no inkling that anyone would make a fuss. Where once there was controversy over the revolving door between public service and the private sector, now there is not even a pause to allow the door to spin. The SE chief executive has set a precedent. No longer need those in her position wait a decent interval before moving from one realm to another. Now they can occupy two spheres simultaneously, with official blessing, and sense no contradiction.

Supposedly, the money is the least of it. In one sense, that's true. In the circles in which the entitlement to a bonus is taken for granted, in which directorships are picked up by the handful and public service is for suckers, £55,000 is small beer. You can work out the moral implications of that statement for yourself. According to Intertek's annual report 2011, their chief executive, one Wolfhart Hauser, received a bonus of more than £800,000. Wilson isn't robbing a bank.

In the course of being headhunted, and while sitting through all those interviews, she must have kept any doubts well-concealed. Given the outcome, she certainly seems to have spent little time telling the executive search agency that it would be impossible to reconcile her obligations as a public servant with the needs of Intertek. It makes you wonder: how would she define those obligations? What's her understanding of the public realm? Or was an approach from a FTSE 100 company its own justification?

The world, as the old song goes, is ill-divided. That's no accident, nor is it Lena Wilson's doing. In her version of the world she has been granted an opportunity and she has seized it. Her chairman calls this an achievement, and calls it remarkable. What I deem remarkable is the extent to which such people, and the politicians who surround them, can be utterly oblivious to the effects of their behaviour. They even seem to be surprised that there could be controversy over Wilson's job on the side.

We pay close to £300 million a year for our enterprise agency. That's after a period in which SE was reformed and cut down to size amid hundreds of redundancies. The idea, in the jargon, was to "refocus" the economic development effort for Scotland. No-one mentioned providing private sector opportunities for people incapable of understanding that the very idea of £55,000 for 12 days work is offensive to those who provide that £300m.

You have to be wholly detached from the society you claim to represent to achieve that frame of mind. You have to feel at all times worthy of the rewards, and believe you are in the right. Presumably, you must therefore assume every critic to be wrong. You represent enterprise, after all – it's on the sign above the door – and they do not. What's so wrong with private reward at public expense?

Let's start with "everything", and work our way down.