Greg

“Those who plead their cause in the absence of an opponent can invent to their heart's content, can pontificate without taking into account the opposite point of view and keep the best arguments for themselves, for aggressors are always quick to attack those who have no means of defence.”
― Christine de Pizan, Der Sendbrief vom Liebesgott / The Letter of the God of Love

“They dispute not in order to find or even to seek Truth, but for victory, and to appear the more learned and strenuous upholders of a contrary opinion. Such persons should be avoided by all who have not a good breastplate of patience.”
― Giordano Bruno

“The most important tactic in an argument next to being right is to leave an escape hatch for your opponent so that he can gracefully swing over to your side without an embarrassing loss of face.”
― Stephen Jay Gould

“There can be no progress without head-on confrontation.”
― Christopher Hitchens, Love, Poverty, and War: Journeys and Essays