In debate, do not nitpick the little stuff in your opponent’s argument. Instead, help make your opponent’s argument as strong as you can. Correct his weak spots for him. Then offer counters to what you consider the strongest version of your opponent’s argument – try to anticipate your own cheap criticisms. Make your opponent the best partner you can. For the goal is not to win the debate, but for you both to better approximate the truth.
— by Sabio Lantz
Addendum: I am please to discover (7 months after this post) that this principle was previously aptly named “The Principle of Charity” back in 1958. I thought I should note it. This should not be surprising, as it seems rather common sense.