How to be a critic
Some nice advice via one of my long time heroes, Daniel Dennett in this review.
"First, ... you must attempt to re-express your opponent's position so clearly, vividly and fairly that your opponent says "Thanks, I wish I’d thought of putting it that way." Then, you should list any points of agreement (especially if they are not matters of general or widespread agreement), and third, you should mention anything you have learned from your opponent. Only then are you permitted to say so much as a word of rebuttal or criticism."