人，可以從生物、精神與文化等各個層面來定義，或是這些層面定義的結合。生物學上，人被分類為人科人屬人種，是一種高級動物。精神層面上，人被描述為能夠使用各種靈魂的概念，在宗教中這些靈魂被認為與神圣的力量或存在有關。文化人類學上，人被定義為能夠使用語言、具有復雜的社會組織與科技發展的生物，尤其是能夠建立團體與機構來達到互相支持與協助的目的。

人類對長生不老的癡迷 For ever and ever

Immortality

For ever and ever

人類對長生不老的癡迷

Four narratives and an actuary

四個說法和一個精算師

Immortality: The Quest to Live Forever and How It Drives Civilisation. By Stephen Cave. Crown; 320 pages; $25. Biteback Publishing; ￡20. Buy from Amazon.com, Amazon.co.uk

《長生不老：對永生的追求及其如何推動人類文明》作者：斯蒂芬。卡夫，皇冠出版社。

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

長生不老是人類世世代代所癡迷的目標。從蘇美爾的吉爾伽美什史詩到荷馬史詩，再到舊約故事，數不清的文學作品觸及到這個主題。從中世紀的煉金術士到現代的科幻烏托邦主義者和神秘主義者，千百年來人們孜孜不倦地追求著永生。

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 “narratives”. The first is the simplest, in theory at least: do what the medieval alchemists never managed and discover an elixir 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 narrative. His fourth narrative deals with immortality through achievement, by becoming so famous that one’s name lives on through the ages。

英國哲學家史蒂芬。卡夫在對這個主題的研究中，把人們關于永生的觀念概括為四個基本的“說法”。第一個，也是最簡單的(至少在理論上)：找到中世紀煉金術士們從未找到的一種神藥，從而避免死亡。第二個是再生，即在死后又恢復生命，這是所有三個亞伯拉罕系宗教(基督教、猶太教和伊斯蘭教)所共有的信仰。第三個“說法”是關于非物質的靈魂不死的理念，這種理念的正式形態，至少可以追溯到柏拉圖。第四個，是通過個人成就獲得永生，即，一個人可以使自己變得非常有名，以至于人們將世代記住他的名字。

For the aspiring undying, Mr Cave unfortunately concludes that immortality is a mirage. But his demolition project is fascinating in its own right. The section on the soul is an able attack on the related doctrines of “vitalism”， the soul and mind-body dualism—the intuitive and still widely held body of ideas that hold that living creatures are animated by some sort of supernatural spark, and that an individual’s personality or consciousness can survive death. The chapters on resurrection will interest Christians, as Mr Cave examines how the literal recreation, by God, of dead people’s bodies remains the doctrine 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。

談到那令人神往的永生，很不幸，卡夫先生的結論是，長生不老只是一種幻想。不過，他摧毀這種幻想的論證過程還是很精彩的。在關于靈魂的章節里，作者對與永生相關的“活力論”信條作了有力的抨擊。活力論是一種靈魂(及心靈)與肉體的二元論，這種理念很直觀，并且仍然被廣為接受。它認為，生物是被某種超自然的力量所激活的，個人的特性和知覺在死后仍然存在。書中關于復活的章節肯定會使基督徒們感興趣，卡夫先生在其中討論了上帝使死人復活的故事，解釋了為什么復活到現在仍然是大多數基督教派的信條。在接下來的章節中，卡夫涉及到人的靈魂上天堂或入地獄的話題。

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

卡夫先生的文體清新，像對話式的散文。但讀者可能會覺得他應當涉及更多的話題。比如怎樣能夠更長壽。卡夫先生甚至沒有對新興的抗老醫學做簡單的介紹，抗老醫學的研究者們已經可以在實驗室里把老鼠的壽命延長三分之一甚至更多。

There are a few quibbles. Mr Cave’s repeated claim that the quest for immortality drives every human activity feels overdone. 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 boredom. As the uncountable billions of years tick away, the argument runs, even the most vivacious will come to realise that they have done everything there is to do, hundreds of times. With yet more billions of years looming ahead they will be struck down with a debilitating ennui。

對卡夫先生的書，我有幾點吹毛求疵的意見。例如，他反復強調，對永生的追求是人類所有行為的推動力，這一點似乎言過其實了。另外，他對永生的定義本身可能也會引起爭議。再者，卡夫先生不贊成追求永生(假定能夠實現)的主要論點，仍然是常見的“永生會造成厭倦”的見解。這種見解認為：在活過了算不清的數百萬年之后，即便是最生動活潑的人也終會意識到，世上所有能做的事都被做了幾百次了;如果再活數百萬年的話，只會越來越無聊了。

That argument only applies if these notional immortals are also invincible, and therefore impervious 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 immortal” 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，這種見解能夠成立的前提是：這些假想的長生不老者同時也是刀槍不入者，因而不會被任何事故所損傷。但這種前提是難以成立的，特別是與研究老化的科學成果相悖。這種科學的目的僅僅是延緩老化。確實，卡夫先生引用了一位精算師的估算結果：即使在醫學意義上能夠長生不老的人，平均壽命大約也只有六千年，因為他們也終會由于飛機失事或汽車事故而死去。此外，厭倦看起來不是什么問題：假如一個長生不老的人實在由于活得太長而厭倦了，他隨時可以結束自己的生命嘛。