Perhaps Sir Michael Wilshaw should dust down his copy of Montesquieu's 1748 masterpiece of political thought De l'Esprit des Lois before he ploughs ahead with moving Ofsted into school improvement (pages 16-17).
In it, the French Enlightenment thinker floated the idea of the separation of powers as a structure for good government and a brake on corruption. He argued that it was essential to keep the judiciary (those passing down legal judgments) firmly apart from the legislature (the makers of laws) and the executive (the governmental and civil service enforcers of laws).
Sir Michael would see how avoiding conflicts of interest is best done by making them near impossible structurally. This idea has become largely accepted in the Western world. The merest suggestion of political meddling in a judge's decision throws up images of Stalinist courts.
There are certainly eccentricities: not least the way we in the UK draw our executive top dogs (government ministers) from the legislature - but then we're Brits and we're allowed.
Nonetheless, Montesquieu's arguments remain valid in the 21st-century English school system.
Put simply, the school inspectorate is a bit like a judicial agency. It takes evidence (an inspection) and then passes judgement on whether a school is succeeding or failing.
Think what you will of Ofsted's practices, but it is very hard to argue with its raison d'etre: independently telling us - the people - which schools are doing well, and which not so. Better, certainly, than relying on cold data.
Similarly, it is hard to argue against the need for a group of wise educationalists working with schools (manned, of course, by teachers, paid members of the executive) to improve standards.
But - and this is a big but - what if the inspectorate were to pass judgement on a school that it itself had been paid to improve? "Mon Dieu," Montesquieu would surely say. "How appalling for a school, staff and pupils to achieve an outstanding at inspection, only for outsiders to whisper about the Ofsted school improvement partner it had worked with."
Sir Michael seemed to get this not-terribly-challenging point at his 2011 confirmation hearing in the Commons, when he said: "Once Ofsted gets involved in the improvement process then it inspects itself and that would be silly."
Only, frustratingly, he now seems to have changed his tune, last week describing his conversion to the idea of his organisation's working in school improvement as a "Damascene moment".
There can be no doubt that Ofsted and its inspectors should make a very real effort to humanise their judgements, explain where improvements can be made and even offer informal advice.
But not as active agents of school improvement.
This argument should be especially at the forefront of Sir Michael's mind at the very moment that he extends his inspectors' remit into passing judgement on local authorities for their work in, ahem, school improvement.
It may not be as satisfying as transforming the lives of pupils through active intervention (in the style of, say, a superhead), but inspection is what Ofsted is there to do. And that is all it should do.