A man states a truth, which may be one-sided. I state its counter-truth, anxious to escape from the one-sidedness of error. It is a strange thing, that middle station between opposites. It is more than a “juste milieu.” It is the key-stone of an arch which props the two sides; and, sure enough, it is no contradiction, if your “juste milieu” contradicts the two extremes. The key-stone of an arch is not antagonistic to the two sides it supports. Being itself neither the one or the other, it upholds both.