Given that one of the fundamental principles of intellectual freedom is the right to challenge any argument, members of the audience were rather taken aback when, in the closing minutes, Ms Phillips rounded on her critics with an explosion of eloquent pique.
"I'm very struck by the complacency of my critics," she said, "and by the supercilious contempt with which they have swept aside the passionate concerns which I have reported as a journalist". Those who interpreted her argument as an attack on teachers were displaying just the sort of "travesty of reason I have found so terrifying while researching my book".
She had a point - the book is not so much an attack on teachers as on the specious ideas with which they have supposedly been corrupted - but Ms Phillips seemed to be questioning peoples' right to question her thesis. In other words, if you dare to doubt her, you must be part of the problem. This outburst was surprising because many of the voices from the floor were supportive; speaker after speaker stood up to offer the opinion that the English education system is indeed putrescent, and that Britain is sinking to the bottom of the world league table.
The fact that Ms Phillips writes from a centre-Left standpoint has been taken to indicate a growing consensus on education, but there was little consensus in evidence at this meeting - apart, that is, from one sublime moment when the education correspondent from Living Marxism stood up and laid claim to the territory normally occupied by Chris Woodhead. If we give prizes to everyone, said the Marxist, we denigrate academic excellence, and teachers who witter on about "resources" and blame parents for all their problems are "wimpish and depressing".
Melanie Phillips' asserts that education in this country is in ruins, fatally infected from nursery to university by a pusillanimous moral relativism which holds that nothing is any more worthwhile than anything else.
Facts - grammar, arithmetic, rules and dates - the fundamental building blocks of education, have been wantonly discarded in favour of sloppy notions about children's spontaneity and self-esteem, against a social backdrop in which morality has been replaced by "choices". Teachers are told that they are mere "facilitators" of learning and are too cowed by dogma to teach as they would wish.
Ms Phillips writes persuasively, but, as John Dunford, former president of SHA, pointed out, her evidence is less impressive than her polemic, being mainly anecdotal. She has unearthed some university dons prepared to say that students arrive without even a basic grounding in their subjects, despite top grades at A-level, and that today's university degrees are not worth the paper they are written on, and a number of teachers disgusted by their training courses and parents dissatisfied with their children's schools. But the rest is theory, asserted as fact, and research evidence is thin on the ground.
Tessa Blackstone said she thought the book would produce "more anger than constructive questioning", and the debate was certainly marked more by a predictable reiteration of entrenched, polarised positions than what Chris Woodhead optimistically called "a new willingness to reflect dispassionately on cherished beliefs".
But most surprising was the absence of anybody prepared to attack Ms Phillips' proposed solution to the sickness in education: the idea that education policy should be transferred from the Department for Education to SCAA, and that the chair of SCAA should be a crown appointment, just like the chief inspector. "It would be Parliament that would ultimately decide on the content of the curriculum," she says. How this would protect education from the pernicious influence of ideology and politics in the future is difficult to see.
All Must Have Prizes by Melanie Phillips, Little, Brown, Pounds 17.50