四元数的诞生,如同几何、代数、形而上学和诗歌这四位父母的奇特后代。
科学家之间的合作是解决复杂问题的关键。
The freedom then of man, and liberty of acting according to his own will, is grounded on his having reason, which is able to instruct him in that law he is to govern himself by, and make him know how far he is left to the freedom of his own will.