I stumbled across a collection of Margaret Atwood's essays at a used bookstore today and while perusing it two paragraphs leapt out to me:
Book reviews I think are the most difficult form for me. It's easy in them to be flip and dismissive, to make jokes at the book's expense, to sneer at the author; some papers think of this as being "controversial" or "readable." But if you're an author yourself you know how much time and effort has gone into a book, even a bad book, and you can't take it so lightly. A reviewer has a responsibility to the public, but she also has a responsibility to the book; you have to try and see and say what is actually there.
Longer critical essays are less painful. For one thing, you know they aren't going to damage sales and affect someone's livelihood, because they are usually post facto and printed in little magazines or academic journals. They also allow more room, for judicious reconsideration, for more complex evaluation than is usually possible in (for instance) The Globe and Mail, and for that luxuriant weed of academe, the footnote. If the book review leans a little towards Consumer Reports, the critical essay is perhaps more like talking to yourself. It's a way, too, of finding out what you really think.
Margaret Atwood, Second Words: Selected Critical Prose (Toronto: Anansi, 1982), 13.