Serious argument depends on mutual respect, and this is often hard to engender when disagreements turn vehement. The social psychologist and game theorist Anatol Rapoport (creator of the winning Tit-for-Tat strategy in Robert Axelrodâ€™s legendary prisonerâ€™s dilemma tournament) once promulgated a list of rules for how to write a successful critical commentary on an opponentâ€™s work. First, he said, you must attempt to re-express your opponentâ€™s position so clearly, vividly and fairly that your opponent says â€œThanks, I wish Iâ€™d thought of putting it that way.â€ 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. I have found this a salutary discipline to followâ€“or, since it is challenging, to attempt to follow. When it succeeds, the results are gratifying: your opponent is in a mood to be enlightened and eagerly attentive.

Here’s a wonderful excerpt from a book review written by Daniel Dennett , in which he paraphrases Rapaport on how to argue constructively.