Who hasn’t heard the philosophical slogan “Know thyself”? The phrase has a long, long pedigree. It’s said to go back to that most ancient of ancient Greek philosophers, Thales of Miletus, who lived in sixth century BC, and Plato tells us that it was inscribed at the entrance to the famous temple of Apollo at Delphi. It’s still popular today, over 2500 years later.

Most people seem think that knowing themselves is a good idea, or at leastsaythat that’s what they think. “Know thyself,” is uttered reverently—as though it’s self-evidently a wonderful goal. Didn’t Socrates say that the unexamined life isn’t worth living? Self-knowledge is supposed to liberate us, to make us happier, healthier, and more productive. Self-help books and psychotherapy mavens sing its praises as an existential panacea.

显然，一定程度的自知之明是一件好事。例如，知道我喜欢寿司可以帮助我选择午餐吃什么。但这种轻量级的、平淡无奇的自我认识并不像“认识你自己”那样庄严。” “Know thyself” soundsdeep—就像一个伟大的探索的召唤，从那里一个人出现作为一个转变和改进的人。好吧，我要引用另一个希腊哲学原则来给这句古老的格言蒙上一些阴影，这个原则来自亚里士多德:“一切都有节制。”凡事过份都是不好的，自知之明也不例外。

我要对自我认知进行审判，我要在前面说，辩方的论据看起来很薄弱。我现在请控方证人出庭。

First up is old Thales. It was the Roman writer Diogenes Laertius who said in his popular, gossipy bookLives of the Eminent Philosophersthat it was Thales who put the “know thyself” meme into circulation. Diogenes lived six hundred years after Thales died, so there’s no telling how accurate his report is, but it’s worth noting that he also attributed another quip about self-knowledge to Thales—one that isn’t mentioned nearly as often as “know thyself.” Diogenes told his readers that Thales said that knowing yourself isthe most difficult thing in life．

Wow. That’s quite a mouthful. Saying that is saying that no matter what difficulties you or anyone else has experienced in life, or whatever tasks, however gargantuan, you or anyone else has taken on, knowing yourself iseven harder．这比忍受折磨、赢得奥运金牌或形成广义相对论要困难得多。

If Thales was right, then anyone pursuing self-knowledge is in for a lot of work, to put it mildly. So if you’re contemplating setting foot on the path to personal enlightenment, you might want to reconsider. And my next three witnesses make self-knowledge sound even more off-putting.

Your honour, I call Immanuel Kant to the stand….

Fast-forward to the 18thcentury, and we find Kant, who is regarded by some as the greatest philosopher of the Enlightenment, if not of all time, warning us that self-knowledge destroys mental health. He wrote dolefully about the “hard descent into the Hell of self-knowledge” that leads to “the gloomiest melancholia.” “Melancholia” was an old term for severe depression, so he’s basically saying that if you embark on the path to self-knowledge, then you’d better keep your bottle of Prozac handy.

如果这还不够糟，我们下一位证人的证词甚至会对辩方的案子造成更大的伤害。下一位证人，我请约翰·沃尔夫冈·冯·歌德出庭。

Around the same time as Kant was warning us about self-knowledge damaging our mental health, another German heavy-hitter pushed the envelope even further. Goethe was a polymath—he was a scientist-poet-novelist-playwright-critic—and he’s regarded as one of the greatest intellects of his age. Goethe described “know thyself” as a con, because it presents people with an impossible demand. ““了解你自己”这一伟大的责任，听起来是如此重要，但我却一直怀疑，就像牧师们的一个秘密阴谋，他们想用无法满足的要求来迷惑人们，引导人们远离他在外部世界的正当活动，进入虚假的内心冥想。他承认他宁愿逃跑也不愿认清自己。如何来吗?

My next witness, Mr. Mark Twain, gives us an answer:“Man, know thyself—& then thou wilt despise thyself, to a dead moral certainty” and my final witness, Twain’s contemporary, the philosopher Friedrich Nietzsche added “This digging into one’s self, this straight, violent descent into the pit of one’s being, is a painful and dangerous undertaking. A man who does it may easily take such hurt that no physician can heal him.”

At this point, if not before, council for the defense might utter, “Objection, your honor! This is all hearsay. These so-called expert witnesses are merely offering opinions, without a shred of evidence behind them.” And that’s just the opportunity I’d need for thecoup de grace．我就能让一群心理学家在法庭上列队列队，他们可以引用实证研究证明:自我欺骗和心理健康是相伴而生的，抑郁的人对自己和他人的看法比那些“形影不离”的人更现实。

This is all pretty damning. If these world-class thinkers are to be believed, self-knowledge sounds like something that we ought to try to steer clear of (or maybe not, since Goethe claimed it’s unachievable anyway). But it’s not yet time to rest my case, because there’s something that’s awfully unclear in these proceedings. We’ve been examining the pros and (mostly) cons of self-knowledge, without ever having clarified what self-knowledge is supposed to be. That will be the topic of next month’s blog.

Photo byBill OxfordonUnsplash