Here's an interesting quote I found in a piece on passive smoking:
"Their conclusion was that ‘public consensus about the negative effects of passive smoke is so strong that it has become part of a truth regime that cannot be intelligibly questioned’."
It is only fair to note that this 'truth regime' springs up in every era (witch hunts, criminilized homosexuality, drugs laws, sexual inequality etc. have all been created by intransigent morality rather than hard logic) Whilst the list in brackets above has been dissapated by current societal mores, there seems to be quite a few new things that can no longer be 'intelligibly questioned' - global warming, smoking, paedophilia, child rearing, racism, rape...and soon even eating & drinking seem like they will be tightly monitored and constricted.
How did the libertarian acid house generation, who are now the urban dwelling bien pensant parents of our new crop of children, become such a massively prescriptive bunch?