How to compose a successful critical commentary:
- You should attempt to re-express your target’s position so clearly, vividly, and fairly that your target says, “Thanks, I wish I’d thought of putting it that way.”
- You should list any points of agreement (especially if they are not matters of general or widespread agreement).
- You should mention anything you have learned from your target.
- Only then are you permitted to say so much as a word of rebuttal or criticism.
From Intuition Pumps And Other Tools for Thinking by Daniel C. Dennett. Quoted in BrainPickings.