My boss recently bought a couple of books that he expected my team to read.
In the past when previous bosses have done this, I've generally gained a lot out of reading the books, even if I disliked some aspects of their arguments I've been able to get a lot of insight from the arguments and evidence presented.
But this book is complete garbage. Truly first rate trash. It barely qualifies as a book. Conquer Your Rebrand, is ostensibly meant to be a business strategy guide to branding. But it is more like a long winded LinkedIn post. It's clearly an attempt by the author to fill his sales pipeline that's barely disguised as him passing on 'expertise.' It presents no compelling arguments, no evidence, is severely lacking in any sort of citations and is written like someone desperately trying to flog a timeshare at a weekend convention. I have redlined the shit out of it but I got so infuriated reading it that I can't imagine how to have a decent discussion with my boss about this book without seeming like my low opinion of this book reflects back on him (which in reality it really does.)
I think it's so much worse because I just finished two brilliant books on my own time —Jack Welsh: The Man Who Broke Capitalism and When McKinsey Comes To Town: The Hidden Influence of The World's Biggest Consulting Firm — that both present compelling arguments, detailed referencing and excellent writing.
How would you handle this?
Oh its a very thin line to tread sometimes in office politics. Do not merely drop that line and leave it hanging, there has to be some padding around it.
The larger point is what OP wants to say. If they do not want any sort of confrontation, lie. Its OK to lie to your boss if its not directly related to work.
If you want to be honest but not engage in any further discussion these statements convey that I think. Sometimes you actually want to say "I think that person is not qualified and will never learn" but leave the option for the other party to gloss over that statement.
Don't try to be clever by saying one thing and meaning another. Be clear about what you want to communicate and then how to communicate it.