IMMORTALITY² is an age-old obsession³. Plenty of literature deals with the subject, from the Sumerian Epic⁴ of Gilgamish to the poems of Homer and the writings of the Old Testament⁵. The quest to live for ever has motivated medieval alchemists, modern techno-Utopians and mystics through the centuries。

长生不老是人类世世代代所痴迷的目标。从苏美尔的吉尔伽美什史诗到荷马史诗，再到旧约故事，数不清的文学作品触及到这个主题。从中世纪的炼金术士到现代的科幻乌托邦主义者和神秘主义者，千百年来人们孜孜不倦地追求着永生。

In his survey of the subject, Stephen Cave, a British philosopher, argues that man’s various tales of immortality can be boiled down into four basic “narratives⁷”. The first is the simplest, in theory at least: do what the medieval alchemists never managed and discover an elixir⁸ to simply avoid dying. The second concerns resurrection, or coming back to life after dying, a belief found in all three of the Abrahamic religions. The idea of an immaterial soul that can persist through death dates back, in a formal form, at least to Plato, and forms Mr Cave’s third narrative⁶. His fourth narrative deals with immortality through achievement, by becoming so famous that one’s name lives on through the ages。

英国哲学家史蒂芬。卡夫在对这个主题的研究中，把人们关于永生的观念概括为四个基本的“说法”。第一个，也是最简单的(至少在理论上)：找到中世纪炼金术士们从未找到的一种神药，从而避免死亡。第二个是再生，即在死后又恢复生命，这是所有三个亚伯拉罕系宗教(基督教、犹太教和伊斯兰教)所共有的信仰。第三个“说法”是关于非物质的灵魂不死的理念，这种理念的正式形态，至少可以追溯到柏拉图。第四个，是通过个人成就获得永生，即，一个人可以使自己变得非常有名，以至于人们将世代记住他的名字。

For the aspiring⁹ undying, Mr Cave unfortunately concludes that immortality is a mirage¹⁰. But his demolition¹¹ project is fascinating in its own right. The section on the soul is an able attack on the related doctrines¹³ of “vitalism”， the soul and mind-body dualism—the intuitive and still widely held body of ideas that hold that living creatures are animated¹⁴ by some sort of supernatural spark, and that an individual’s personality or consciousness can survive death. The chapters on resurrection will interest Christians¹⁵, as Mr Cave examines how the literal recreation, by God, of dead people’s bodies remains¹⁶ the doctrine¹² of most branches of Christianity. The idea of one’s soul, as opposed to one’s body, ending up in heaven or hell is a subsequent embellishment。

谈到那令人神往的永生，很不幸，卡夫先生的结论是，长生不老只是一种幻想。不过，他摧毁这种幻想的论证过程还是很精彩的。在关于灵魂的章节里，作者对与永生相关的“活力论”信条作了有力的抨击。活力论是一种灵魂(及心灵)与肉体的二元论，这种理念很直观，并且仍然被广为接受。它认为，生物是被某种超自然的力量所激活的，个人的特性和知觉在死后仍然存在。书中关于复活的章节肯定会使基督徒们感兴趣，卡夫先生在其中讨论了上帝使死人复活的故事，解释了为什么复活到现在仍然是大多数基督教派的信条。在接下来的章节中，卡夫涉及到人的灵魂上天堂或入地狱的话题。

If anything, readers might want more of Mr Cave’s crisp conversational¹⁷ prose. There could be more on living longer; Mr Cave barely has time to give even the briefest overview¹⁸ of the emerging science of life extension, which has allowed researchers to lengthen¹⁹ the lifespans of mice by a third or more in the lab。

卡夫先生的文体清新，像对话式的散文。但读者可能会觉得他应当涉及更多的话题。比如怎样能够更长寿。卡夫先生甚至没有对新兴的抗老医学做简单的介绍，抗老医学的研究者们已经可以在实验室里把老鼠的寿命延长三分之一甚至更多。

There are a few quibbles. Mr Cave’s repeated claim that the quest for immortality drives every human activity feels overdone²⁰. Others might dispute his definition of immortality itself. Mr Cave’s chief argument against the desirability of living for ever (even assuming it is possible) is the familiar one of boredom²¹. As the uncountable billions of years tick away, the argument runs, even the most vivacious²² will come to realise that they have done everything there is to do, hundreds of times. With yet more billions of years looming²³ ahead they will be struck down with a debilitating²⁴ ennui²⁵。

对卡夫先生的书，我有几点吹毛求疵的意见。例如，他反复强调，对永生的追求是人类所有行为的推动力，这一点似乎言过其实了。另外，他对永生的定义本身可能也会引起争议。再者，卡夫先生不赞成追求永生(假定能够实现)的主要论点，仍然是常见的“永生会造成厌倦”的见解。这种见解认为：在活过了算不清的数百万年之后，即便是最生动活泼的人也终会意识到，世上所有能做的事都被做了几百次了；如果再活数百万年的话，只会越来越无聊了。

That argument only applies if these notional immortals²⁶ are also invincible²⁷, and therefore impervious²⁸ to accident. But that is an odd definition, and not one that crops up very often, especially in scientific research into ageing. The holy grail there is simply to arrest the ageing process. Indeed, Mr Cave quotes an actuary who has estimated that the average “medical immortal¹” would persist for around 6,000 years before dying in a plane accident or a car crash or the like. And besides, boredom seems to be a non-problem: after all, if an immortal does ever get truly bored of his vastly extended life, there would be nothing to prevent him from ending it。

然而，这种见解能够成立的前提是：这些假想的长生不老者同时也是刀枪不入者，因而不会被任何事故所损伤。但这种前提是难以成立的，特别是与研究老化的科学成果相悖。这种科学的目的仅仅是延缓老化。确实，卡夫先生引用了一位精算师的估算结果：即使在医学意义上能够长生不老的人，平均寿命大约也只有六千年，因为他们也终会由于飞机失事或汽车事故而死去。此外，厌倦看起来不是什么问题：假如一个长生不老的人实在由于活得太长而厌倦了，他随时可以结束自己的生命嘛。