認清反轉基因邏輯，你將學會批判性思考_風聞

前言：在前一篇文章《為何不證明“轉基因是安全的”的邏輯推導》中，我們瞭解到了為何在邏輯層面，許多反轉基因的理由是站不住腳的，如同我們無法以相同理由證明一杯水是絕對安全的一樣。這些邏輯上的硬傷是構成當今反轉基因理論的致命漏洞，本文由國外作者發表的文章重點分析了反轉基因勢力的主要幾個觀點，並從中分析了13個自我相互矛盾以及邏輯層上的誤區，來指明瞭反轉基因觀點到底在什麼地方是荒謬和錯誤的。文中總結的許多反轉基因輿論戰特點在我國的反轉基因輿論場中也同樣適用。本文引用部分為UP本人根據國內反轉基因團體的真實行為補充了一些觀點。

友情提示：Alt + F4 鍵可以迅速關閉本文並封閉自己的視野。我認為可以幫助某些人節約不必要看文章的時間。

原題：有關轉基因生物的爭論是體現批判性思維的一個重要研究案例。

反轉基因運動的考驗期到了。在過去的幾年中，Amy Harmon, Nathaneal Johnson, Keith Kloor, Micheal Specter等人國內知名科學記者已經把抵制轉基因運動相關言論批得體無完膚了。三週前，Slate雜誌就禁用、標註轉基因食品一事也提出了諸多質疑。

值得稱讚的是一些轉基因批評者，似乎願意接受反轉基因運動改革了。作為Just Lable It（標註轉基因）運動的領導者，Gary Hirshberg因為一些毫無科學依據的言論被轉基因支持者攻擊了。但他最新文章已有跡象表明他厭惡了“轉基因食品危險有害”這類言論。他正在試圖重新把焦點轉移到有關（轉基因食品生產與銷售）透明度，除草劑的應用，長期監測問題的爭論上來。

還有一部分人一意孤行地抹黑轉基因的安全性。Claire Robinson是他們的頭兒，他是GM Watch的主編並且還是地球資源研究所的研究員。兩年前，Johnson為了Grist雜誌的系列報道，就轉基因運動的論戰雙方展開了調查。 Robinson當時指責Johnson是在美化（轉基因）產業鏈。現在Robinson已經為Slate雜誌完成了系列文章的撰寫。Robinson的論點站不住腳，但他們這樣做還是有意義的。通過探究這些常見的反轉基因的錯誤，你至少可以學到很多關於如何批判性思考的知識。以下是一些經驗之談。

1）不要迷信權威。

Robinson曾説過你不應該輕易相信科研機構的模糊判斷。我同意她的觀點。這也是我為什麼要深入探究四個案例以尋求確切證據的原因。我指的是證據，而不是什麼擔保，我要的是能揭開轉基因爭論的真面目的確鑿證據。因此當Robinson試圖通過呼籲權威而掩蓋證據，引用偽造的諸如美國環境科學組織時（該組織是一個偽裝成學術仲裁協會的冒牌組織），不要上當受騙。

在國內，一些反轉組織和博客經常性歪曲甚至篡改國外發布的科研數據報告，比如比較著名的“直言了（一個反轉博客博主）歪曲美國國務院報告數據進行造假。因此在查閲這些看似由權威機構發佈的觀點時，要求對方能夠提供原文全文，並且讓自己有一定的原文閲讀能力是非常必要的。（UP補充註釋，後同）

2）小心概念泛化。

Robinson引用了世界衞生組織的一份聲明：“不同的轉基因生物包括不同基因按不同的方式插入生物體內。這意味着，個別轉基因食品及其安全性的評估應該具體問題具體分析，因此我們不可能對所有轉基因食品的安全性一概而論。”她把上述聲明作為需要更加嚴格規範轉基因生物的論據。Robinson犯了個錯，其實那個聲明僅僅是説：不可過於粗糙寬泛地對食品進行分類隔離，每種食品都應根據自身特點進行評估。轉基因標識才是犯了這樣的錯誤，分類隔離其實是完全不必要的。

3）仔細閲讀細則。

為了用草甘膦來嚇唬人。Robinson從自然雜誌上節選了一個標題：“癌症和廣泛使用的除草劑有關”

。她把標題放在圖表之中，這樣你就不能點進網頁鏈接進一步閲讀原文。如果你去查那篇文章，你又會發現很多警告性的詞句“風險是無法定量的”，而且那篇文章所援引的科學家自己都説“此處援引的證據顯得有點薄弱”。孟山都公司指出，草甘膦已經被劃分為類似咖啡，手機這類可能致癌物質之列。不要相信公司的把戲，但也不要相信反企業的把戲。

與國內反轉勢力的觀點如出一轍，凡討論轉基因，反轉人士勢必會抬出“孟山都罪不可赦”的觀點來。雖然孟山都在轉基因作物方面有許多成果，但並不能抹殺其他企業在這個行業努力的成果。而反跨國公司的把戲本質也是一種陰謀論。

4）尊重證據。

Robinson説，“你們不能相信我，因為我曾説過無人駕駛飛機減少了平民傷亡。”我的證據顯示上述結論是正確的。但你**可能會用不同的方式去解讀。**但重要的是，我把事實都擺在桌面上，這樣我們就可以對它們進行討論、檢驗我們之前的數據假設。如果遵循Robinson這種可笑荒謬的先驗命題，那麼你將一無所獲。

先預設立場，再尋找證據，當證據出現相反或者不符合他們需求的時候，選擇性無視。這個問題在許多反轉勢力中經常出現，許多反轉人士會發表許許多多觀點，許多觀點也一樣是從網上摘抄的，但他們在摘抄這些觀點的時候，從來就沒考慮過從相反觀點搜索一下，許多他們發表的這些觀點，早就被別人批駁過反擊過，已經是過時的了。更甚的當然是選擇性無視，這在許多持反轉基因觀點的論文中經常出現——即無視了那些無法與論文觀點應徵的實驗數據。相關例子有許多就不再舉出。

5）保持開放的思想，願意聽取他人的意見。

Robinson指出，我最初支持伊拉克戰爭，後來後悔了，最後寫了一篇關於我從錯誤中學到教訓的文章。她自嘲有一個很糟糕的歷史觀，還讓讀者們不要輕信她。她的手段已經落伍了。你不該相信那些自己都拒絕接受新知識的人。當事情沒有按照你期望的方向發展時，你必須重新思考你的假設，否則你會一直死守教條。

在國內，理性的轉基因話題討論是不存在的，這點就是我之前的簽名觀點，如今仍然在堅持，所以我始終不認為我能説服幾個反轉人士，我發文章從來就不指望是給他們看的。

6）仔細檢查每件事。

在Slate的文章中，我對轉基因批評家選擇性的監督行為表示了不滿——**他們一方面誇大轉基因的風險，而另一方面卻對非轉基因替代品的風險輕描淡寫。**其中有一個例子是關於植入了病毒基因的木瓜。評論員們把那個轉基因木瓜描述得十分危險可怕，儘管人們其實已經安全食用含有同樣病毒的木瓜好多年了。Robinson做的這組對比存在漏洞，因為通過基因工程技術改變結構的病毒與天然病毒並不相同。她聲稱轉基因的嵌入過程和隨後轉基因過程中的組織培養會產生突變。這些會引發植物產生生化反應，反過來也可能使得植物意外產生毒素或過敏物質。但是突變並不是轉基因生物所特有的，突變是隨處可見的，尤其是在植物育種上更是十分平常。如此説來，非轉基因生物過敏或中毒的可能性其實更大。

我也很早就在評論區指出，對於轉基因食品的安全需求，同樣應當用於驗證非轉基因食品，而反轉人士對此的反駁只能是一句“老祖宗吃了幾千年就是沒問題的”蒼白無力的回覆。因為他們知道，他們提出的這些安全指責站不住腳，也不可能實現，提出這些觀點，並不是他們真正關心食品安全，而只是故意給轉基因食品找茬，給轉基因食品豎起一個不可逾越的門檻罷了。

7）比較選項。

如果有人告訴你某件事情很糟糕，那你就用同樣的標準來判斷它的替代品。**以草甘膦事件為例，轉基因評論員説草甘膦有害，但奇怪的是他們對草甘膦的替代品——其它除草劑的毒性卻緘口不言。**Robinson質疑我引用美國農業部報道，農業部報道説“抗除草劑作物已經使農民們不得不採用一種毒性更大，藥效更持久的除草劑來代替原先的草甘膦了。”

Robinsn認為美農業部的報道並不意味着草甘膦“相對良性”。但農業部就是這麼説的“相對良性”。你調查一下就會發現隨着草甘膦的使用越來越廣泛，其他很多毒性更大的農藥除草劑使用量越來越少了。如果你研究了世界衞生組織的農藥安全性等級排名，你就會發現草甘膦其實屬於第二等危險品，大多數之前被草甘膦取代的除草劑毒性更大。

我之前也一直重複過，反轉人士認為草甘膦不好，是否能提出一個比草甘膦毒性更低，效果更好的除草劑來取代草甘膦，而再另一篇不相關文章中，甚至有輿論開始為毒性更強的百草枯強行洗地。

8）留意改變規則。

Slate報道過那些自詡為專家的反轉激進分子在夏威夷提供虛假證詞（他們中至少有一個曾經得到過Robinson的保護）。那幾個人作證説轉基因木瓜從來沒有接受過動物安全監測。我提供了發表在農業和食品化學雜誌的一項研究予以回應，那項研究裏面提到了用轉基因木瓜餵食過老鼠。Robinson不僅不承認證詞是假的，她還拋出了另一個大膽言論。她聲稱老鼠研究的證據剛好與轉基因木瓜的安全性相矛盾。看來她又犯了一個錯誤。那份研究報告（報告需要付費才能查看）指明瞭“沒有遺傳毒性”、“沒有生物顯著差異，”和“無生物的不利影響。”

Robinson還説，在老鼠身上做的這項安全監測研究太短了。以防萬一科學家會繼續研究下去，Robinson也準備好了對策---再次轉移目標。即使在牛身上持續做兩年研究也是不夠的（Robinson稱牛兩年壽命相當於人類八年）。指控和要求是沒完沒了，如果一直你試圖找尋更高的標準和新的合理性藉口，那你只是在為你的觀點做偽證而已。

轉基因食品沒有做過安全檢測 —— 不正確，轉基因做過，我可以拿出相關實驗的報告 —— 沒用！做了兩年完全不夠，要百年三代。前面這個情景總能出現在大量反轉人士發表的觀點中。沒完沒了的藉口。

9）注意政治動機。

Robinson完全無視黃金大米緩解維生素A缺乏症的功效，她眼中的黃金大米就是一個轉基因海報的代言人、一個用以攻擊生物技術產業評論員的武器。**但是如果你硬要從政治層面看每件事情，你無疑無法看到根本現實。**大米是食物，維生素是一種營養素。**如果你僅僅因為你認為黃金大米是另一方的武器而反對一個營養項目，那你才是玩弄政治手腕的人。**這種“我們”對抗“他們”的思維方式可以帶壞任何人。在轉基因生物的案例中，它已經帶壞了太多的環保主義者和公共健康倡導者。

政治陰謀論，扣帽子，你是孟山都的槍手，拿錢發帖，光觀網自己的評論區，這些低劣的觀點就屢見不鮮，我都被扣過無數頂這樣的帽子，這是所有反轉人士在拿不出實證攻擊轉基因後的最後手段——人身攻擊，污名化。雖然即便我從來都沒説過孟山都如何如何，我説的最多的都是國產轉基因作物。

10）小心商業動機。

Robinson不相信任何與孟山都公司有聯繫的人做的轉基因研究。但她對於自己和有機消費者協會的關係卻覺得沒什麼，有機消費者協會代表着幾千家天然食品和有機市場企業，這一協會也會從強制性的轉基因標識中受益良多。Robinson還稱轉基因木瓜的失敗是因為“市場排斥”，但正是反轉基因羣體大大推動了市場排斥。在這場論戰中，孟山都不是唯一操縱市場的公司，**反轉基因羣體同樣影響着消費市場。**請睜大眼睛，從正反兩個方面來看這個問題。

崔永元的淘寶食品店給我們上了一堂該觀點的真實生動的課程，不再重複。

11）謹防陰謀論。

Robinson説，Slate的那篇報道是“政治”產物，因為共和黨領導的眾議院前腳剛公佈全面禁止強制性

打轉基因標籤，Slate的報道隨後就馬上發表了。對於我而言，這還真算得上是一個新聞點，我當時都還不知道眾議院要表決了。至於Robinson還暗示我是一個狂熱的共和黨人，並且我的同事們都在與共和黨合作，任何讀過Slate雜誌的人大概都會覺得此番言論很有趣吧。不要成為痴迷陰謀論的傻瓜，陰謀論總是貌似給你敲警鐘，但事實上你正在一步步掉入陷阱而渾然不覺。

任何話題只要進入陰謀論環節就沒啥可以討論的了，轉基因也一樣，畢竟拿不出實證來輔佐自己觀點，總能靠陰謀論的邏輯來掩蓋。諸如轉基因是美國滅亡中國的陰謀的這樣的觀點，在中文網絡中多如牛毛。

12）檢查你的行為是否有悖價值觀。

如果你發現自己對抵制高營養價值作物失敗耿耿於懷，還振振有詞不成功絕不停止抵制這些作物。或者説你可以完全漠視15%的菲律賓的幼兒和學齡前兒童缺乏維生素A，覺得這事兒也沒什麼大不了的，你最好捫心自問你是怎麼才有這種抵制想法的。

我不信美國轉基因，我支持國產的，我只反對轉基因主糧，我支持國家對轉基因的研究。這三點我已經批駁過很多了，事實上反轉人士掛在嘴邊的這三點除了與事實相反，也與他們自身相互矛盾。

13）顧全大局。

Robinson毫不理會Slate報道中涉及的兩項案例研究。那兩項案例指出轉基因木瓜是“小範圍種植”和並且黃金大米也並沒有在市場流通。**但如果你無視一項技術的最佳應用方法，並且你限制或者禁止它因為你也不喜歡其他的應用程序，你排除了所有可能性。**那為什麼你要給轉基因食品貼上一個轉基因標籤，把轉基因大米，木瓜，和土豆劃分到耐除草劑的類別中去？基因工程是一種技術，不是一類食品，禁止轉基因技術是在把這項技術帶給人類的福祉拒之門外。

**我無法保證任何轉基因食品都是安全的，而Roinson卻能保證每一個非轉基因食品都是安全的。**這一點上，我輸給她了。我寫這篇文章不是為了向各位讀者輸入某種理念或者打贏一場口水戰。我只是想讓大家學會批判性思考。如果你遵循了以上13條法則，在抵制轉基因運動中，你就能避免犯大錯。而且你就能擺脱教條主義的束縛，包括那些宣稱代表懷疑的人們也是如此。

原作者： William Saletan 是Slate雜誌的專欄作者，為該雜誌撰寫政治、經濟、科學、科技等相關話題內容； Bearing Right一書的作者。原文鏈接：http://www.slate.com/articles/health_and_science/science/2015/08/critical_thinking_lessons_for_the_anti_gmo_movement_generalizations_evidence.html?wpsrc=sh_all_dt_tw_top

編譯：楊寧

翻頁查看英文原文

Food for Thought

The debate over genetically modified organisms is a great case study in how to think critically.

By William Saletan    

It’s gut-check time for the anti-GMO movement. In the past couple of years, some of the  country’s best science journalists—Amy Harmon, Nathanael Johnson, Keith Kloor, Michael Specter, and others—have shredded many of the movement’s claims and arguments. Three weeks ago Slate poked more holes in the case for banning or labeling genetically engineered food.

Some GMO critics, to their credit, seem open to reforming the movement. Gary Hirshberg, the chairman of Just Label It, has been pounded by GMO advocates for unscientific statements. But in his latest essay, Hirshberg shows tentative signs of turning away from allegations that GMOs per se are dangerous. He’s trying to refocus the debate on transparency, herbicidal applications, and long-term monitoring.

Others are clinging to the same old discredited attacks on GMO safety. Chief among them is Claire Robinson, an editor at GMWatch and researcher for Earth Open Source. Two years ago, when Johnson investigated issues on both sides of the GMO debate for a series in Grist, Robinson accused him of parroting industry spin. Now Robinson has written a three-part series leveling a similar charge at Slate. Her arguments fail, but they do so in an instructive way. By exploring these common anti-GMO errors, you can learn a lot about how to think critically, and not just about GMOs. Here are some of the lessons.

No. 1: Don’t rely on authority. Robinson says you shouldn’t settle for vague assurances from scientific organizations. I agree. That’s why I drilled down into four case studies to look at specific evidence. The evidence, not the assurances, is what debunks the arguments against these GMOs. So when Robinson tries to drown out that evidence with her own appeals to authority, citing bogus “science-related organizations” such as the American Academy of Environmental Medicine—a quack group dressed up as an association of scholarly referees—don’t fall for the act.

No. 2: Beware of generalizations. Robinson quotes a statement from the World Health Organization: “Different GM organisms include different genes inserted in different ways. This means that individual GM foods and their safety should be assessed on a case-by-case basis and that it is not possible to make general statements on the safety of all GM foods.” She portrays this as an argument for regulating GMOs more strictly than non-GMOs. She’s wrong. The statement means exactly what it says: Instead of segregating food into clumsy, overbroad categories, each product should be assessed on its own merits. That’s the problem with GMO labeling: It’s unwarranted segregation.

No. 3: Read the fine print. To scare you about glyphosate, an herbicide that is used in tandem with some genetically engineered crops, Robinson displays a headline from Nature: “Widely used herbicide linked to cancer.” She puts the headline in a graphic, so you can’t click through to read the article. If you look up the article, you’ll find caveats: The risk is unquantified, and according to an expert quoted in the story, “the evidence cited here appears a bit thin.” The article also debunks a claim from Monsanto, which has implied, misleadingly, that glyphosate has been put in the same possible-carcinogen category as coffee and cellphones. Don’t trust the corporate spin. Don’t trust the anti-corporate spin, either.

No. 4: Respect evidence. Robinson says you can’t trust me because I’ve “claimed that drones cut down on civilian casualties.” Guilty as charged. Here’s my evidence that the drones claim is true. You may interpret it differently. But the important thing is that I’ve put facts on the table so we can debate them and test our assumptions against data. If you follow Robinson’s approach—ridiculing propositions as absurd a priori—you’ll learn nothing.

No. 5: Keep an open mind. Robinson points out that I initially favored the Iraq war, later regretted it, and eventually wrote about lessons I learned from my mistake. She says this shows I have “a history of bad judgment calls,” and therefore you shouldn’t trust me. She has it backward. The people you shouldn’t trust are those who reject new information. When events or experiments don’t turn out as you expected, you have to rethink your assumptions. Otherwise you end up clinging to dead dogmas.

No. 6: Scrutinize everything. In the Slate article, I accused GMO critics of selective scrutiny: playing up the risks of GMOs while playing down the risks of non-GMO alternatives. One example was a papaya engineered with a gene from a virus. The papaya has been portrayed as dangerous, even though people have safely eaten non-GMO papayas loaded with the same virus for decades. Robinson says the comparison is faulty because “the genetically engineered form of the virus is not the same as the natural virus.” She claims that “the GM gene insertion and subsequent tissue culture processes used in genetic engineering create mutations. These can result in biochemical changes in the plant, which in turn could make the plant unexpectedly toxic or allergenic.” But mutations are hardly unique to GMOs. They’re ubiquitous, especially in plant breeding. You’re no more likely to get a toxic mutation from a GMO than from a non-GMO.

No. 7: Compare the options. When you’re told something is bad, apply the same standard in judging the alternatives. Glyphosate is a good example. GMO critics say it’s hazardous, but they’re strangely quiet about the herbicides it has replaced. Robinson says the USDA report I cited—which said the adoption of herbicide-tolerant crops “has enabled farmers to substitute glyphosate for more toxic and persistent herbicides”—doesn’t mean glyphosate is “relatively benign.” But that’s exactly what it means. If you look up which pesticides have declined in use as glyphosate has increased, you find many that are far more hazardous. And if you study the World Health Organization’s pesticide safety ratings, you’ll see that glyphosate is in the second-least-hazardous category. Most of the herbicides it has replaced are worse.

No. 8: Watch for moving goalposts. The Slate article reported that anti-GMO activists who present themselves as experts (at least one of whom Robinson had previously defended) gave false testimony in Hawaii. They testified that genetically engineered papayas had never been tested for safety in animals. I pointed to a study, published in the Journal of Agricultural and Food Chemistry, in which the papayas had been fed to rats. Rather than acknowledge that the testimony was false, Robinson simply throws up another claim. She says evidence in the rat study contradicts the “belief that the GM papaya is safe.” This, too, is false: The paper (which is paywalled, sorry) reports “no genotoxicity,” “no biologically significant differences,” and “no biologically adverse effects.”

Robinson also says the study was too short. But just in case scientists follow up with a longer study, she’s ready to move the goalposts again: Even a two-year study in cows (“equivalent to around eight years in human terms,” according to Robinson) isn’t enough. The allegations and demands are endless. When you keep reaching for higher standards and new rationalizations, you’re just protecting your beliefs from falsification.

No. 9: Beware of political agendas. Robinson dismisses Golden Rice, which is engineered to relieve vitamin A deficiency, as “a poster-child for GM” and “a weapon to attack the biotech industry’s critics.” But when you see everything in political terms, you lose sight of the underlying reality. Rice is food. Vitamin A is a nutrient. If you campaign against a nutritional project because you see it as a weapon for the other side, you are the one playing politics. This kind of us vs. them thinking can corrupt anyone. In the case of GMOs, it has corrupted too many environmentalists and public health advocates.

No. 10: Beware of business agendas. Robinson discounts GMO research by anyone who has ever been linked to Monsanto. But she sees no problem with her own connections to the Organic Consumers Association, which represents “several thousand businesses in the natural foods and organic marketplace,” which would benefit from mandatory GMO labeling. Robinson also calls genetically engineered papayas a failure because of “market rejection.” But that’s a circular argument, since anti-GMO groups have been driving much of the market rejection. Monsanto isn’t the only one manipulating the market in this debate. Keep your eyes open, and look both ways.

No. 11: Beware of conspiracy theories. Robinson says the Slate article was “political” because it “was published just before the Republican-led House of Representatives considered a complete ban on mandatory GMO labelling.” That’s news to me, since I didn’t even know the House vote was coming. As for Robinson’s suggestion that I’m a rabid Republican and my colleagues are in cahoots with the GOP, I bet that’s pretty funny to those of you who actually read Slate. Don’t be a sucker for conspiracy theories. They make you feel vigilant, when in fact you’re being credulous.

No. 12: Check your behavior against your values. When you find yourself rooting for the failure of nutritionally enhanced crops, arguing that it’s OK to try to block these crops as long as you don’t succeed, or dismissing vitamin A deficiency in 15 percent of Filipino toddlers and preschoolers as no big deal, it’s time to ask yourself how you got to this point.

No. 13: Think about the big picture. Robinson brushes aside two case studies in the Slate article, noting that genetically engineered papayas are “little grown” and Golden Rice is “unavailable.” But if you ignore the best applications of a technology, and you restrict or ban it because you don’t like other applications, you foreclose its possibilities. Why would you demand a label that puts the rice, the papayas, and safer potatoes in a category with products engineered for herbicide tolerance? Genetic engineering is a technique, not a type of food, and banning it would shut down all the good things it can do.

I can’t promise you every GMO is safe, any more than Robinson can promise every non-GMO is safe. I’m not here to sell you an ideology or win a fight. I’m here to encourage you to think critically. If you follow these 13 rules, you’ll avoid the worst mistakes of the anti-GMO movement. And you’ll free yourself from dogmatists, even those who claim to speak for doubt.