The early Eighties were not an easy time for holding rational views. Margaret Thatcher was emboldened by her Falklands victory to take on "enemies within". We now know from ministerial memoirs that the miners were always in her sights. But so were local councils, the Inner London Education Authority, nuclear disarmers, public sector workers, dissenters at Greenham Common and elsewhere and, inevitably, the "educational establishment".
The National Union of Teachers - I was its head of external relations at the time - became a target of the Prime Minister and the press in its own right. Union press comments had often to be restricted to a single sentence; anything more would be mangled.
Such were the times when Sir Keith was confronted with a demand from the National Council for Educational Standards for taxpayers' money to further its "research" on examination performance. Its controversial findings, launched at the high tide of Thatcherism and with the Prime Minister's apparent approval, were given massive and uncritical coverage not only by the usual Fleet Street suspects, but by the BBC.
As the raw data from which the NCES's controversial conclusions were drawn was not available for independent evaluation, the NUT and its allies had to fall back on pointing up the study's methodological weaknesses in an effort to prevent public money being swallowed up in a blatantly partisan way.
The only obstacle to that was Sir Keith, acting on the advice of his civil servants. We understood that the private pressure on him from No 10 was intense. In public, the most extraordinary episode was the sudden appearance in the Sunday Times of a Yes, Minister script in which the NCES was portrayed as the long-suffering victim of educational orthodoxy.
After a battle lasting months, the Secretary of State threw out the funding application. This wasn't the end of the story but at the time it did represent a minor victory for propriety in public affairs. For that, Sir Keith Joseph should be remembered.
I never met him, but if a mutual acquaintance in New York is to be believed, the independent mind which carried him through the NCES fight turned questioningly, in his final years, to re-evaluating his own role as Mrs Thatcher's monetarist guru. One wonders what this land might now be if those doubts had been expressed long before his retirement.
John Booth is a freelance writer and journalist