I have rewritten this post, having looked at a good bit of Dr Clarke's lecture and his background.
I strongly suspect that he did medicine at the Royal Free and had a hard time because of his own ME/CFS. It looks to me as if he is trying hard to make a serious analysis of the diagnostic and scientific difficulties around ME but starting from the wrong information.
He is handicapped by not being familiar with the published work of the world's most important ME/CFS academic department: the University of Phoenix Rising Faculty of Clinical Sciences, with internationally renowned faculty members.
Maybe someone should tip him a friendly wink?
I had a quick look at his background and couldn't find anything about him having ME himself.
I read the notes (I haven't watched the lecture). He seems to have swallowed Wessely's views uncritically, which is very limited for someone supposedly researching an issue and having a team of students researching an issue. I wonder whether they actually talked to any of the ME patient groups or looked, for example at the MEA purple book. I don't think much of him as a supervisor of research if he thinks it's OK to swallow whole the Wessely spin and not even investigate the other side.
And, like the BBC on climate change he presents it as a balance of equals, not a wrong and a right side. While he explores the different definitions, he doesn't seem to have taken on board the significance of believing research on CBT GET treatments based on the Oxford definition. In fact I don't see that he adds anything useful to the debate, just continues the Wessely misinformation.
I've just found him on Twitter and will endeavour to link him to some better sources of information, including the University of Phoenix Rising.
Edit to add. I've just tweeted him links to this thread, the OMF website highlighting today's conference, and the JHP special issue on PACE.
Brendan, if you have found your way in here, welcome. I'm sure you are serious in your endeavour to understand the ME/CFS issues. It is a pity you appear to have been taken in by Simon Wessely who has a long history of distorting the views of and research on ME/CFS.
I do hope you are open minded, as any good philosopher must be, and willing to learn. Do watch the OMF lectures - they will be on You Tube if you miss them tonight. And do read the JHP journal.