When Sir Adrian Smith steps down as director general for knowledge and innovation at the end of this month, he will be able to look back on a job well done. Unlike others who have sought to make the transition from outside Whitehall, Smith has skilfully navigated his way through the highways and byways of the Westminster village. He has avoided the "gone native" charge and remained a popular and credible figure.
So what of his successor? It remains a distinct possibility that a career civil servant could take up the role. For one, the salary on offer - £140,000 - is unlikely to attract a serving, mid-career vice-chancellor. More to the point, there are many credible people in Whitehall who could do the job.
Some of the most able and effective people I have ever worked with were career civil servants who could turn their hands to the most complex policy and problems. An excellent generalist from this background would be much better for higher education than a mediocre external hire, whatever their supposed credibility.
In 2003-04, when the political drama around the rise in tuition fees to £3,000 a year was at its height, the role of the civil servants who worked behind the scenes was the subject of much praise.
Smart ministers recognise too that good Whitehall operators are invaluable. It helps that the Department for Business, Innovation and Skills is not seen as a no-go department; both Vince Cable, the business secretary, and David Willetts, the universities and science minister, seem refreshingly positive about, and courteous to, their civil servants.
On the other hand, an external appointment could have its advantages. When I first became permanent secretary at the Department for Education and Skills in January 2006, the estimable Sir Alan Wilson was director general of higher education. Wilson's standing in the sector as a former vice-chancellor was a considerable asset. It gave greater prominence to universities. There was also little doubt that he had the ear of his ex-colleagues and that this helped to head off potential problems.
What advice might I offer? For a civil servant, their experience, insight and knowledge of how the system works would all be invaluable and could bring a genuinely new dimension to policymaking. But decisions have to be tested politically and, in these unusual times, "coalition-ised". The good news is that even where ministers have a strong political drive to do something, they usually want the best advice on how to achieve their ends.
Don't forget the privacy of the policymaking space. To air any differences with ministers in public is, rightly, a cardinal sin.
Know your brief. To an outsider, particularly one with expertise in a specific area, the amount expected of you as director general is formidable. Truthfully, there is no substitute for sheer hard work and no shortcut to mastering new areas of policy.
Form alliances. It is no accident that people talk of the Westminster "village". Find out where the real influence lies - ministerial private offices are a good place to begin. Watch and learn from the old hands. Cultivate contacts in other ministries such as the Treasury and, yes, the Department for Education.
Build a strong network with the scientific community across Whitehall. The arrival of Sir Mark Walport as the government's chief scientific adviser presents the opportunity to forge an early alliance with another powerful outsider.
Keep in touch with those in the outside world. The advice you give will be immeasurably improved by first-hand and regular contact with those who are likely to be on the receiving end of policy decisions.
And finally, remember that nothing is ever - ever - off the record as a senior civil servant. I well remember having to manage a rather irate Ed Balls when Smith was presumed to have "gone off the reservation" when talking privately - or so he thought - about qualification reform. So do not be seduced when your ex-colleagues offer you another drink and expect you to reveal what Willetts really thinks.