Some things you want to write much less than others; some you don't want to write at all. This one is in the second such category.

Professor Aidan Halligan has died unexpectedly, aged 57. A friend and mentor to many, he was the NHS's first director of clinical governance, and also deputy chief medical officer to Sir Liam Donaldson.

Once he finished his work on the national stage, Aidan went on to set up and fund training resources for clinicians to help them in leadership. He also went on to improve health services for homeless people in collaboration with UCLH.

Patient leader Roger Kline has written this thoughtful and thorough tribute to Aidan's work; another superb piece by John Walsh is here.

Aidan leaves behind his wife Carol and three daughters.

As well as his considerable professional distinction, Aidan was an outstanding human being. He reminded me greatly of the late Professor Bob Sang, firstly for his relentless focus on patients and their care - and secondly for the very slow progress you could ever make when walking in his company at a healthcare event or conference.

Aidan was, quite simply, loved by a lot of people, who wanted to talk to him, and he had time for them all. He had a rare gift of personal warmth, that ignited a reciprocal feeling in others.

He was also a brave man, personally. I met him in early 2006, shortly whereafter (and not as a direct result), I correctly called for the resignation of then-NHS CE Sir Nigel Crisp with a front cover editorial for British Journal of Healthcare Management: the magazine I then edited. I asked Aidan, among many others, to write a short piece for the next issue of BJHCM on what the NHS needed to do to change and get out of the fix.

His contribution was beautifully written and incendiary in equal measures. Under 'fair usage' terms, I quote some extracts below.

"The instinctive, logical, politically right-headed (and completely wrong) response is to focus exclusively on financial recovery. The spirited solution would be to reflect on the expensive lessons learned, and apply the learning.

"The healthcare system is populated by bright, dedicated, well-intentioned people. Now is the time to surface that talent in meaningful leadership positions across the NHS and, together with smart processes and enabling technology, allow the best mediocre healthcare service in the world to become truly the very best".

This piece was picked up for national attention by BJHCM columnist, FT public policy editor Nick Timmins, and used by opopsition leader David Cameron as a stick to beat PM Tony Blair at PMQs.

To his complete lack of surprise, Aidan was told he had to resign as deputy CMO. He did so without rancour.

Discussing this saga with him some years afterwards, I ventured that he must have been getting good mileage out of the word 'vindicated'. Aidan smiled wryly, and replied that 'the difference between a halo and a noose is only six inches'.

Aidan was one of the good guys, and he told his truth without fear or favour. His truth turned out to look pretty convincing, thanks to subsequent events.

Without Aidan's consistent support, clinical leadership in the NHS (imperfect as it is) would be much less developed than it is.

He didn't seek credit for that, and may not get it. If he doesn't, I'd guess that he wouldn't have minded.

Aidan Halligan wasn't in it for the credit. The proper people never are.