以前對隔行如隔山可以隔到什麼程度，我的想像約莫是數學家與史學家溝通或許會有困難，但是數學家大概可以和物理學家進行有意義的溝通。但後來，我才發現，隔行如隔山，那一行，遠比我以為的要來的窄的多了。不只我的數學家朋友聽不大懂我的理論物理學家朋友在幹嘛（我以為都很「數學」阿），其實連哲學家都未必知道別的哲學家到底在研究什麼。
最近這幾天有篇文章，在我小小的同溫層裡不斷的被轉載。大意就是，有位在美教書的中國籍的教授開除了自己的學生，失望之餘，她寫了這篇文章解釋，為什麼自己最後做出這樣的決定。其實整篇文章寫的懇切，適合搭配著韋伯的學術作為一種志業一起讀。然而，不知道是否是因為這位教授專業並非語言哲學，文中一段提到維根斯坦的Tractatus之處，詮釋的方式，非常有問題。
她說道：
在做學問上，「凡你能說的，你說清楚；凡你不能說清楚的，留給沉默。」（維特根斯坦，Tractatus）在一知半解的時候，你胡說，那叫「擴散無知」，是害人、誤導，是浪費別人生命。
但Wittgenstein未曾說過這句話。我想這句話大概是想要講Tractatus中的Proposition 7: Wovon man nicht sprechen kann, darüber muss man schweigen. “Whereof one cannot speak, thereof one must be silent.” 當無法言說時，必須靜默。所以，單就是「引用」來說，這位教授在文章如此書寫，已經構成了「『擴散無知』，是害人、誤導，是浪費別人生命。」
其二，對Wittgenstein的Tractatus稍微有點瞭解的人都會知道，這個Proposition的詮釋雖多，但要能與其他諸多Propositions相互呼應的詮釋，並沒那麼多。而將之詮釋成這種做學問的道德，很遺憾的，大概不是其中之一。所以，再次的，這是「『擴散無知』，是害人、誤導，是浪費別人生命。」
套這句「凡你能說的，你說清楚；凡你不能說清楚的，留給沉默。」，我其實不大懂，為何不就清清楚楚地說「知之為知之，不知為不知，是知也。」《論語．為政第二．十七》就好了。為什麼要刻意引個在中文世界不大知名的Wittgenstein，而且還引錯呢？
至於這個Proposition到底真正是在說什麼？Philosophy Now的這篇文章介紹的很不錯，我就不再多言：
When everything that can coherently be said about everything has been said, there remains the unsayable, or at least the unsaid – and perhaps also the not-to-be-said, whether from disinclination or prohibition. ‘Mystical’ in English and mystisch in German, from the Greek, have all four senses. The root of ‘mystery’ is muo, ‘to close or to keep shut’, used mainly of the eyes or the mouth, and there are obviously several reasons why one might keep one’s mouth shut. On the one hand, one might have nothing to say. On the other hand, having something to say, (a) one might not be able to think of the words in which to say it; or (b) one might wish not to say it on some particular occasion or perhaps ever; or (c) one might be forbidden to say it, or have sworn not to do so. The Greek Mysteries were mainly of this last sort: there was a communicable doctrine, but it was esoteric, and insiders were enjoined not to speak of it to outsiders. (It is said that when one of the Pythagoreans revealed the incommensurability of the square root of two, the others threw him off a cliff.)
Schweigen (‘be silent’) has elements of all these senses in German but, especially in conjunction with darüber, also some additional overtones. One of the overtones is musical: schweigen as used of a musical performance is to end or to cease: it stands for the falling-silent at the conclusion of a work – for completion, for satisfaction, also perhaps for regret. It is a powerful last word for a book whose structure, according to Erik Stenius, is musical. (There is nothing contradictory in the idea that it might be both religious and musical, like a Bach chorale.) Schweigen however also stands for a sort of civilised reticence: there are things one doesn’t say, that one doesn’t draw attention to, that one passes over in silence. And then there is the silence of the Law: darüber schweigt das Gesetz; “about this the law says nothing” – here you are free to draw your own conclusion, to do as you please. Kant’s project in the first Critique seems to have been (among other things) to show that there are limits to reason and hence concepts that escape its law – concepts that we can adopt as regulative, that we can cherish as grounds for hope. Similarly Wittgenstein’s project in the Tractatus is clearly to show that there are limits to language and to its law. Wittgenstein wrote to Ludwig Ficker that the most important part of the book was the part that was not written. As I once put it in another context, “instead of being primarily concerned with what logic and language include, Wittgenstein by this account cared about that only because it showed what they exclude; rather than drawing the outer boundaries of speech, he was drawing the inner boundaries of silence.”
Tractatus
--
