哲基尔和海德在英文中为什么指事情的两面性？这两个人到底在英语国家的文化中有什么故事背景?

化身博士 (Strange Case of Dr Jekyll and Mr Hyde)

我的正面是善良 另一面是邪恶（上）

《化身博士》也可译作《变身怪医》，这个故事的主角哲基尔医生，由于内心长期的压抑及郁闷(long term repression and boredom)，而发明了一种神奇的化学药物(magic potion)。他把自己当作这种药物的实验对象，于是他摇身一变，变成了邪恶卑鄙的海德先生。哲基尔医生本来是企图通过这样的变化来解放自己，没想到后来却一发不可收拾。这种变身是善恶交战的一种体现，也是真实生活中人性的缩影。

《化身博士》是罗伯特-路易斯-史蒂文森所写的一部小说。这个故事讲述了一个试图将人性善恶分隔成两面的人。善良的一面是哲基尔医生，而邪恶的一面则是海德先生。

起初，认识哲基尔和海德的人并不了解他们其实就是同一个人。他们只知道哲基尔医生做了很多好事，而海德先生做了很多坏事。比如说，海德伤害了街上的一个年轻女孩；而哲基尔却拿钱帮助了这个女孩的家人。

Strange Case of Dr Jekyll and Mr Hyde is the original title of a novella written by the Scottish author Robert Louis Stevenson and first published in 1886. The work is commonly known today as The Strange Case of Dr Jekyll and Mr Hyde or Dr Jekyll and Mr Hyde.[1] It is about a London lawyer named Gabriel John Utterson who investigates strange occurrences between his old friend, Dr Henry Jekyll,[2] and the misanthropic Edward Hyde.

The work is known for its vivid portrayal of a split personality, split in the sense that within the same person there is both an apparently good and an evil personality each being quite distinct from the other. The novella's impact is such that it has become a part of the language, with the phrase "Jekyll and Hyde" coming to mean a person who is vastly different in moral character from one situation to the next.[3]

Strange Case of Dr Jekyll and Mr Hyde was an immediate success and is one of Stevenson's best-selling works. Stage adaptations began in Boston and London within a year of its publication and it has gone on to inspire scores of major film and stage performances.