An ignorant man believes that the whole universe only exists for him: as if nothing else required any consideration. If, therefore, anything happens to him contrary to his expectation, he at once concludes that the whole universe is evil. If, however, he would take into consideration the whole universe, form an idea of it, and comprehend what a small portion he is of the Universe, he will find the truth. There are many ... passages in the books of the prophets expressing the same idea.
MaimonidesAll the evils that men cause to each other because of certain desires, or opinions or religious principles, are rooted in ignorance. [All hatred would come to an end] when the earth was flooded with the knowledge of God.
MaimonidesWhile one man can discover a certain thing by himself, another is never able to understand it, even if taught by means of all possible expressions and metaphors, and during a long period; his mind can in no way grasp it, his capacity is insufficient for it.
Maimonides