I've spent quite a bit of time in this thread and come away (feeling) considerably more enlightened. Thank you in particular for those reviews, glenster. I very much enjoyed Hitchens' God is not Great treatise, to the extent that I listened to it three times (the audiobook is narrated by Hitchens himself, which adds an insightful dimension of vocal inflection to the words.) I must confess that I took much of what Hitchens is saying on face value - that he would not be so unwise as to expose himself to unsubstantiated statements - and I am now just a little disillusioned after reading Peterson's critical review. I would be interested to see Hitchens' rebuttal, if one indeed exists.
Like so many things, it is a necessary challenge within the pursuit of truth to separate out bald fact from the words in which it is spun. In that sense, everything we read needs to be treated with at least some small measure of scepticism, including the contributions of the reviewers of Hitchens', Dawkins' and Harris' books.