温伯格《解释世界》第五章 古代科学与宗教

前苏格拉底时代的希腊学者在探索自然现象过程中逐步忽视宗教，这迈出了朝向现代科学的一大步。但这种对旧束缚的挣脱仅仅是初步，不够完善。我们在第一章看到，戴奥真尼斯·拉尔修对泰勒斯教义的描述，其中讲到不只“水是宇宙基本物质”，而且“世界生机勃勃，充满神灵。”尽管如此，仅从留基波和德谟克里特的讲授中就可以发现一个新的开端已经开启。他们流传下来有关物质特性的描述中没有一处提及上帝。 将宗教从研究自然中脱离开来对科学的发现意义重大。这个过程历经几个世纪，一直到十八世纪才在物理科学领域得以实现，在生物学领域则需要更长时间。 并不是说现代科学家都不相信存在超自然之力（尽管我确实这样认为，但也有一些杰出科学家笃信宗教），这里的思路是如果不用假设超自然力的干预，我们的研究可以进展到什么程度。只有这样我们才能投入科学研究，因为一旦引入超自然力，一切皆可解释，却又无法验证。所以说目前宣传的“智能设计论”不是科学—而是科学的对立面。 柏拉图的思考模式充满了宗教色彩。在《蒂迈欧篇》中他描述了神如何将行星放置到各自运行轨道，他可能认为行星本身也是神灵。虽然希腊化时代哲学家摒弃了众神灵，但其中一些学者以人类价值观和情感来描述自然。因为相对于毫无生机的世界，他们显然更钟情于人类社会。我们前面看到，在讨论物质变化时，阿那克西曼德说道正义，恩培多克勒讲到争斗。柏拉图认为元素和自然的其他方面之所以值得研究不是在于自然本身，而是因为对他来说这体现了一种美德，呈现于大自然及人世间。这是他的宗教观，如《蒂迈欧篇》所述：“上帝要求一切近善，无恶。因此，当他俯视世界，发现物体不是处于静止状态，而是无序，紊乱地运动，他将无序恢复为有序，在他眼里后者远远优于前者。 今天我们仍在探索自然规律，但是我们并不认为自然规律会源于人文价值。但是不是所有人都赞同这点。二十世纪伟大的物理学家埃尔温·薛定谔就主张回到古代那种科学与人文价值交融的时代。本着同样的精神，历史学家亚历山大·科耶夫认为科学与现今我们所谓的“哲学”的分离是场“灾难”。我本人认为这种想用整体论探索自然的方法是科学家一直极力摆脱的，因为很简单我们在自然定律中没有发现任何因素与美德，正义，爱或斗争有任何关系，哲学不能为科学解释提供可靠指导。 我们不知道异教徒们为何笃信自己的宗教。那些周游过四方或阅读广泛的希腊人知晓欧洲，亚洲和非洲信仰众多神明。有些希腊人将之理解为这是不同名字下的相同神灵。虔诚的历史学家希罗多德讲述说并不是埃及人敬奉的女神丕贝色特与希腊女神阿耳特弥斯相似，而是他们以丕贝色特之名敬奉阿耳特弥斯。其他希腊人认为这些神灵完全不同，他们都真实存在。一些奥林匹斯之神是从亚洲引入的，比如狄俄尼索斯和阿芙罗狄蒂。 多神观在一些希腊人中助长了无神论。前苏格拉底时代的色诺芬尼有一段名言：“埃塞俄比亚人信仰的神灵扁鼻，黑发，色雷斯信仰的神灵则拥有灰色的眼睛，红色的头发。”他又评说：“如果牛（或马）或狮子有手，或能像人那样可以用手做画并创作艺术作品，那么马画出来的神将像马，牛画的神像牛，它们各自按自身描画各自神的体型。” 历史学家修昔底德与希罗多德不同，他没有一点宗教信仰的迹象。他谴责雅典将军尼西亚斯做出的灾难性决策，因为月蚀尼西亚斯做出了推迟从与叙拉古战场撤军的决定。修昔底德认为尼西亚斯“过于迷信占卦一类东西。” 怀疑论在那些积极探索自然的希腊学者中开始变得特别普及。我们前面看到，德谟克里特有关原子的猜想完全是自然主义思想。德谟克里特的观点被作为对抗宗教的有利武器而广为接受。萨摩斯的伊壁鸠鲁首先接受了这个观点，他生活在雅典，在希腊化时代早期创建雅典花园学院。伊壁鸠鲁又激励了罗马诗人卢克莱修，他的长诗作品《物性论》深埋于修道院图书馆，直到1417年才被重新发现，该书对欧洲文艺复兴产生了深远影响。斯蒂芬·格林布拉特追溯了卢克莱修对马基雅弗利，莫尔，莎士比亚，蒙田，伽森狄（注：皮尔· 伽森狄为法国神父和哲学家，曾试图融合伊壁鸠鲁以及卢克莱修的原子论与基督教。），牛顿，以及杰斐逊的影响。即使在没有放弃异教之地，希腊人也在渐渐趋向于把它寓意为探索真相的线索。正如吉本所言：“极端荒唐的希腊神话，用一种清晰可闻的声音宣告，一个虔诚的探索者，不能为它的表面涵义吓住，或满足于它的表面涵义，而必须勤奋地去探索小心谨慎的古人有意掩藏在愚昧和寓言之中的深奥难测的智慧”。这种对隐藏智慧的探求导致了罗马时代现称为新柏拉图派哲学的兴起，该派哲学由普罗提诺和他的学生波菲利在三世纪创立。虽然新柏拉图派哲学家并没有什么科学创新，但他们延续了柏拉图崇尚数学的精神。例如波菲利创作了毕达哥拉斯传记以及欧几里德《几何原本》评注。寻求隐藏于表面之下的真相是科学工作的主要任务，因而毫不奇怪新柏拉图主义者至少保留了对科学的兴趣。

异教徒不太关心维护各自的私人信仰。异教徒那里没有像圣经或古兰经那样的权威教义。《伊利亚特》，《奥德赛》，以及赫西俄德的《神谱》都被认为是文学作品，而非神学作品。有许多诗人和牧师是异教徒，但没有神学家。那时公开宣称无神论仍很危险。至少在雅典政治辩论中会用指责对方为无神论者作为武器，不信异教众神的哲学家们会感受到来自政府的压力。前苏格拉底时代哲学家阿那克萨哥拉由于讲授太阳只是比伯罗奔尼撒半岛大的一块发热的石头，不是神，而被驱逐出雅典。 柏拉图尤其极力维护宗教在自然研究中的作用。他对教授德谟克里特的无神化思想极为愤慨，在《法律篇》第十卷裁定在他的理想国任何人如果拒绝承认神的真实存在，干涉人间事物，都应该被罚以5年单独监禁，如果其后还不思悔改，则应处以极刑。 在这一点如同在其他许多方面一样，亚历山大精神与雅典精神截然不同。我没有看到任何希腊化时代科学家在他们的作品中表示过对宗教的兴趣，我也不知晓他们中的任何人由于不信宗教而受到过惩罚。 罗马帝国时代并非没有宗教迫害。这并不是说其反对外来众神。罗马帝国晚期万神殿包括了弗里吉亚自然女神西布莉，埃及女神伊希斯，以及波斯密特拉神。但是不管一个人信仰什么其他宗教，他首先必须保证忠于政府，而且必须公开奉行罗马法定宗教。据吉本所述，罗马帝国各种宗教“大众认为全部可信，哲学家认为全部虚假，官员认为全部有用。”基督教教徒受到迫害并不是由于他们信奉耶和华或耶稣，而是他们公开拒绝罗马国教。如果他们在罗马神坛放一炷香，他们一般就会获得赦免。 这些在罗马帝国都没有影响到希腊科学家的研究工作。喜帕恰斯和托勒密从来没有因为他们关于行星的无神化理论而受到任何迫害。虔诚的异教徒朱利安皇帝谴责伊壁鸠鲁的追随者，但是并没有迫害他们。 虽然基督教由于拒绝罗马国教而被定为违法，但在公元二世纪和三世纪仍然广为传播。公元313年君士坦丁大帝将基督教合法化，公元380年狄奥多西大帝将基督教定为罗马帝国唯一合法宗教。希腊科学的伟大成就到此就到了尽头。历史学家自然而然怀疑是否基督教的兴起与原创科学的衰败存在联系。 过去人们非常关注宣传宗教与科学发现间可能发生的冲突。比如哥白尼将他的巨著《天体运行论》献给教皇保罗三世，在献辞中他警告人们不应采用圣经中的章节来否定科学工作。他引述了君士坦丁长子的基督教导师拉克坦提乌斯的极端例子： 也许有一些“空谈家”，他们对数学一窍不通，却自称是这门学科的行家。他们从圣经中断章取义，为达到自己的目的而加以曲解，他们会对我的著作吹毛求疵，并妄加非议。我不会理睬他们，甚至认为他们的批评是无稽之谈，予以藐视。众所周知，拉克坦提乌斯可以说是一位杰出的作家，但不能算作一位数学家。他很幼稚地谈论地球的形状，并嘲笑那些宣称地球是球形的人。（1985年译） 这种评论并不是很公平。拉克坦提乌斯确实说过天空不可能处于地球下面。他辩称如果世界为球形，那就会存在生活在地球相反方向的人和动物。这很荒唐，人和动物并不一定非要生活在地球的每一个角落。而且即使确有人和动物生活在地球相反方向，那又有什么问题哪？拉克坦提乌斯认为他们会摔到“天底”。他之所以接受亚里士多德（引用时没有提到他的名字）相反的观点—“物体的自然特性是落向地球中心”—是为了指责那些“用荒谬证明荒谬”的人。当然荒谬的人是拉克坦提乌斯，但是不像哥白尼所认为的那样，拉克坦提乌斯依据的不是圣经，而是一些极其浅陋的涉及自然现象的观点。总之，我不认为圣经与科学知识的直接冲突是造成基督教与科学紧张关系的主要缘由。 在我看来更为重要的是早期基督徒中盛传的一种观念，他们认为异教徒科学分散了人们真正应该关注的事物的实质。这种观念可以追溯到基督教初期，圣保罗警告说：“你们要谨慎，以免有人用他们的哲理，和虚妄的谎言毁了你们，他们只是参照人间传统和世界雏形，而不是遵循基督。”这其中最著名的是神父德尔图良在公元200年的发问：“雅典与耶路撒冷有什么关系？学院与教堂又有什么关系？”（德尔图良这里用雅典和学院来代表希腊化时代哲学，可能是因为他对雅典和柏拉图学院比对亚历山大的科学更为熟悉）。在神父希波的奥古斯丁的论述中体现出对异教的反省意识。奥古斯丁年轻时学习希腊哲学（只是通过拉丁文译本），曾非常自豪自己对亚里士多德哲学的领悟，但是后来他问道：“当我深陷邪恶淫荡之中，我去阅读和理解那些所谓的“人文”著作时对我有什么好处哪？”奥古斯丁同样关注基督教与无神论哲学的冲突。他在晚年回顾早年作品，于公元426年做出了如此评述：“我非常不满自己早年对柏拉图，柏拉图学派以及学院派哲学家等没有宗教信仰的人的过渡吹捧，特别是那些错误地反对捍卫传授基督教的人。” 另外基督教给那些才智过人的年轻人提供在教会晋升的机会，这些年轻人不然可能会成为数学家或科学家。主教和长老一般会获得民事法庭以及税收方面的豁免。像亚历山大的西里尔或米兰的安布罗斯这样的主教可以行使庞大的政治权力，他们的权力要比亚历山大博学院或雅典学院学者大很多。这是一种新的现象。在异教社会拥有财富和政治权利的人会任职教会，而不是任职教会的人会变得有钱有势。比如朱利亚斯·凯撒和他的继任者持有最高主教的职务并不是由于他们的虔诚和博学，而是由于他们手里所拥有的政治权利。 希腊科学在基督教盛行之后接着持续了一段时间，但仅仅是做了些对早期科学工作的评注。哲学家普罗克鲁斯公元5世纪任教于罗马新柏拉图学派继任的柏拉图学院，他撰写了对欧几里德《几何原本》的评注，其中有些原创性东西。在第八章我会引用到柏拉图学院后期学者辛普里丘在评注亚里士多德时对柏拉图关于行星运行轨道的评论。公元四世纪后期亚历山大里亚的西昂撰写对托勒密巨著《天文学大成》的评注，而且筹备了欧几里德作品的改进版本。他有一位很出名的女儿希帕提娅，后来成为亚历山大新柏拉图学派的领导者。一个世纪后基督徒菲洛波努斯的约翰在亚历山大里亚撰写了亚里士多德评注，他批评了亚里士多德有关运动的学说。约翰认为向上抛出的物体之所以不会立刻下落不是因为亚里士多德所讲的物体受到空气携带作用，而是当物体被抛出后物体具有了一种维持运动的特性，类似后来的动力或动量观点。但是再也没有出现欧多克斯，阿里斯塔克斯，喜帕恰斯，欧几里德，厄拉多塞，阿基米德，阿波罗尼奥斯，希罗或托勒密这样富有创新能力的科学家和数学家。 无论是否由于基督教的兴起所致，很快连评注也消失的无影无踪。希帕提娅公元415年被主教亚历山大里亚的西里尔唆使的暴徒谋杀，但不知是出于宗教还是政治原因。公元529年查士丁尼皇帝（他收复了意大利和非洲，编纂了罗马法典，在君士坦丁堡兴建了宏伟的圣索非亚教堂。）下令关闭了雅典新柏拉图学院。关于此事件，虽然吉本在谴责基督教，但他的描述如此生动和富有说服力，我们不能不在此引用： 哥特的武力对雅典学校所造成的危害还不及一个新宗教的建立；这一宗教的教士们以自己的见解代替理智，一切问题都凭藉对神的信条来决定，任何不信神或对神抱有怀疑思想的人都被认为应抛入永恒的地狱烈火中去。在许多大卷大卷的辩论文字中，他们揭露理解力的虚弱和人心的堕落，在古代的圣哲身上对人性加以诋毁，并禁止那种与一个平凡信徒的理论，或至少和他的性格大相抵触的哲学的探索精神。 罗马帝国希腊部分一直维持到公元1453年。但是我们在第九章会介绍到，其实在这之前科学研究的中心早已东移到了巴格达。

The pre-Socratic Greeks took a great step toward modern science when they began to seek explanations of natural phenomena without reference to religion. This break with the past was at best tentative and incomplete. As we saw in Chapter 1, Diogenes Laertius described the doctrine of Thales as not only that “water is the universal primary substance,” but also that “the world is animate and full of divinities.” Still, if only in the teachings of Leucippus and Democritus, a beginning had been made. Nowhere in their surviving writings on the nature of matter is there any mention of the gods. It was essential for the discovery of science that religious ideas be divorced from the study of nature. This divorce took many centuries, not being largely complete in physical science until the eighteenth century, nor in biology even then. It is not that the modern scientist makes a decision from the start that there are no supernatural persons. That happens to be my view, but there are good scientists who are seriously religious. Rather, the idea is to see how far one can go without supposing supernatural intervention. Only in this way can we do science, because once one invokes the supernatural, anything can be explained, and no explanation can be verified. This is why the “intelligent design” ideology being promoted today is not science—it is rather the abdication of science. Plato’s speculations were suffused with religion. In Timaeus he described how a god placed the planets in their orbits, and he may have thought that the planets were deities themselves. Even when Hellenic philosophers dispensed with the gods, some of them described nature in terms of human values and emotions, which generally interested them more than the inanimate world. As we have seen, in discussing changes in matter, Anaximander spoke of justice, and Empedocles of strife. Plato thought that the elements and other aspects of nature were worth studying not for their own sake, but because for him they exemplified a kind of goodness, present in the natural world as well as in human affairs. His religion was informed by this sense, as shown by a passage from the Timaeus: “For God desired that, so far as possible, all things should be good and nothing evil; wherefore, when He took over all that was visible, seeing that it was not in a state of rest but in a state of discordant and disorderly motion, He brought it into order out of disorder, deeming that the former state was in all ways better than the latter.”1 Today, we continue to seek order in nature, but we do not think it is an order rooted in human values. Not everyone has been happy about this. The great twentieth-century physicist Erwin Schrödinger argued for a return to the example of antiquity,2 with its fusion of science and human values. In the same spirit, the historian Alexandre Koyré considered the present divorce of science and what we now call philosophy “disastrous.”3 My own view is that this yearning for a holistic approach to nature is precisely what scientists have had to outgrow. We simply do not find anything in the laws of nature that in any way corresponds to ideas of goodness, justice, love, or strife, and we cannot rely on philosophy as a reliable guide to scientific explanation. It is not easy to understand in just what sense the pagans actually believed in their own religion. Those Greeks who had traveled or read widely knew that a great variety of gods and goddesses were worshipped in the countries of Europe, Asia, and Africa. Some of the Greeks tried to see these as the same deities under different names. For instance, the pious historian Herodotus reported, not that the native Egyptians worshipped a goddess named Bubastus who resembled the Greek goddess Artemis, but rather that they worshipped Artemis under the name of Bubastus. Others supposed that these deities were all different and all real, and even included foreign gods in their own worship. Some of the Olympian gods, such as Dionysus and Aphrodite, were imports from Asia. Among other Greeks, however, the multiplicity of gods and goddesses promoted disbelief. The pre- Socratic Xenophanes famously commented, “Ethiopians have gods with snub noses and black hair, Thracians gods with gray eyes and red hair,” and remarked, “But if oxen (and horses) and lions had hands or could draw with hands and create works of art like those made by men, horses would draw pictures of gods like horses, and oxen of gods like oxen, and they would make the bodies [of their gods] in accordance with the form that each species itself possesses.”4 In contrast to Herodotus, the historian Thucydides showed no signs of religious belief. He criticized the Athenian general Nicias for a disastrous decision to suspend an evacuation of his troops from the campaign against Syracuse because of a lunar eclipse. Thucydides explained that Nicias was “over-inclined to divination and such things.”5 Skepticism became especially common among Greeks who concerned themselves with understanding nature. As we have seen, the speculations of Democritus about atoms were entirely naturalistic. The ideas of Democritus were adopted as an antidote to religion, first by Epicurus of Samos, who settled in Athens and at the beginning of the Hellenistic era founded the Athenian school known as the Garden. Epicurus in turn inspired the Roman poet Lucretius. Lucretius’ poem On the Nature of Things moldered in monastic libraries until its rediscovery in 1417, after which it had a large influence in Renaissance Europe. Stephen Greenblatt6 has traced the impact of Lucretius on Machiavelli, More, Shakespeare, Montaigne, Gassendi,* Newton, and Jefferson. Even where paganism was not abandoned, there was a growing tendency among the Greeks to take it allegorically, as a clue to hidden truths. As Gibbon said, “The extravagance of the Grecian mythology proclaimed, with a clear and audible voice, that the pious inquirer, instead of being scandalized or satisfied with the literal sense, should diligently explore the occult wisdom, which had been disguised, by the prudence of antiquity, under the mask of folly and of fable.”7 The search for hidden wisdom led in Roman times to the emergence of the school known to moderns as Neoplatonism, founded in the third century AD by Plotinus and his student Porphyry. Though not scientifically creative, the Neoplatonists retained Plato’s regard for mathematics; for instance, Porphyry wrote a life of Pythagoras and a commentary on Euclid’s Elements. Looking for hidden meanings beneath surface appearances is a large part of the task of science, so it is not surprising that the Neoplatonists maintained at least an interest in scientific matters. Pagans were not much concerned to police each other’s private beliefs. There were no authoritative written sources of pagan religious doctrine analogous to the Bible or the Koran. The Iliad and Odyssey and Hesiod’s Theogony were understood as literature, not theology. Paganism had plenty of poets and priests, but it had no theologians. Still, open expressions of atheism were dangerous. At least in Athens an accusation of atheism was occasionally used as a weapon in political debate, and philosophers who expressed disbelief in the pagan pantheon could feel the wrath of the state. The pre-Socratic philosopher Anaxagoras was forced to flee Athens for teaching that the Sun is not a god but a hot stone, larger than the Peloponnesus. Plato in particular was anxious to preserve the role of religion in the study of nature. He was so appalled by the nontheistic teaching of Democritus that he decreed in Book 10 of the Laws that in his ideal society anyone who denied that the gods were real and that they intervened in human affairs would be condemned to five years of solitary confinement, with death to follow if the prisoner did not repent. In this as in much else, the spirit of Alexandria was different from that of Athens. I do not know of any Hellenistic scientists whose writings expressed any interest in religion, nor do I know of any who suffered for their disbelief. Religious persecution was not unknown under the Roman Empire. Not that there was any objection to foreign gods. The pantheon of the later Roman Empire expanded to include the Phrygian Cybele, the Egyptian Isis, and the Persian Mithras. But whatever else one believed, it was necessary as a pledge of loyalty to the state also to publicly honor the official Roman religion. According to Gibbon, the religions of the Roman Empire “were all considered by the people, as equally true, by the philosopher, as equally false, and by the magistrate, as equally useful.”8 Christians were persecuted not because they believed in Jehovah or Jesus, but because they publicly denied the Roman religion; they would generally be exonerated if they put a pinch of incense on the altar of the Roman gods. None of this led to interference with the work of Greek scientists under the empire. Hipparchus and Ptolemy were never persecuted for their nontheistic theories of the planets. The pious pagan emperor Julian criticized the followers of Epicurus, but did nothing to persecute them. Though illegal because of its rejection of the state religion, Christianity spread widely through the empire in the second and third centuries. It was made legal in the year 313 by Constantine I, and was made the sole legal religion of the empire by Theodosius I in 380. During those years, the great achievements of Greek science were coming to an end. This has naturally led historians to ask whether the rise of Christianity had something to do with the decline of original work in science. In the past attention centered on possible conflicts between the teachings of religion and the discoveries of science. For instance, Copernicus dedicated his masterpiece On the Revolutions of the Heavenly Bodies to Pope Paul III, and in the dedication warned against using passages of Scripture to contradict the work of science. He cited as a horrible example the views of Lactantius, the Christian tutor of Constantine’s eldest son:

But if perchance there are certain “idle talkers” who take it on themselves to pronounce judgment, though wholly ignorant of mathematics, and if by shamelessly distorting the sense of some passage in Holy Writ to suit their purpose, they dare to reprehend and to attack my work; they worry me so little that I shall even scorn their judgments as foolhardy. For it is not unknown that Lactantius, otherwise a distinguished writer but hardly a mathematician, speaks in an utterly childish fashion concerning the shape of the Earth, when he laughs at those who said that the Earth has the form of a globe.9

This was not quite fair. Lactantius did say that it was impossible for sky to be under the Earth.10 He argued that if the world were a sphere then there would have to be people and animals living at the antipodes. This is absurd; there is no reason why people and animals would have to inhabit every part of a spherical Earth. And what would be wrong if there were people and animals at the antipodes? Lactantius suggests that they would tumble into “the bottom part of the sky.” He then acknowledges the contrary view of Aristotle (not quoting him by name) that “it is the nature of things for weight to be drawn to the center,” only to accuse those who hold this view of “defending nonsense with nonsense.” Of course it is Lactantius who was guilty of nonsense, but contrary to what Copernicus suggested, Lactantius was relying not on Scripture, but only on some extremely shallow reasoning about natural phenomena. All in all, I don’t think that the direct conflict between Scripture and scientific knowledge was an important source of tension between Christianity and science. Much more important, it seems to me, was the widespread view among the early Christians that pagan science is a distraction from the things of the spirit that ought to concern us. This goes back to the very beginnings of Christianity, to Saint Paul, who warned: “Beware lest any man spoil you through philosophy and vain deceit, after the tradition of men, after the rudiments of the world, and not after Christ.”11 The most famous statement along these lines is due to the church father Tertullian, who around the year 200 asked, “What does Athens have to do with Jerusalem, or the Academy with the Church?” (Tertullian chose Athens and the Academy to symbolize Hellenic philosophy, with which he presumably was more familiar than he was with the science of Alexandria.) We find a sense of disillusion with pagan learning in the most important of the church fathers, Augustine of Hippo. Augustine studied Greek philosophy when young (though only in Latin translations) and boasted of his grasp of Aristotle, but he later asked, “And what did it profit me that I could read and understand all the books I could get in the so-called ‘liberal arts,’ when I was actually a slave of wicked lust?”12 Augustine was also concerned with conflicts between Christianity and pagan philosophy. Toward the end of his life, in 426, he looked back at his past writing, and commented, “I have been rightly displeased, too, with the praise with which I extolled Plato or the Platonists or the Academic philosophers beyond what was proper for such irreligious men, especially those against whose great errors Christian teaching must be defended.”13 Another factor: Christianity offered opportunities for advancement in the church to intelligent young men, some of whom might otherwise have become mathematicians or scientists. Bishops and presbyters were generally exempt from the jurisdiction of the ordinary civil courts, and from taxation. A bishop such as Cyril of Alexandria or Ambrose of Milan could exercise considerable political power, much more than a scholar at the Museum in Alexandria or the Academy in Athens. This was something new. Under paganism religious offices had gone to men of wealth or political power, rather than wealth and power going to men of religion. For instance, Julius Caesar and his successors won the office of supreme pontiff, not as a recognition of piety or learning, but as a consequence of their political power. Greek science survived for a while after the adoption of Christianity, though mostly in the form of commentaries on earlier work. The philosopher Proclus, working in the fifth century at the Neoplatonic successor to Plato’s Academy in Athens, wrote a commentary on Euclid’s Elements, with some original contributions. In Chapter 8 I will have occasion to quote a later member of the Academy, Simplicius, for his remarks, in a commentary on Aristotle, about Plato’s views on planetary orbits. In the late 300s there was Theon of Alexandria, who wrote a commentary on Ptolemy’s great work of astronomy, the Almagest, and prepared an improved edition of Euclid. His famous daughter Hypatia became head of the city’s Neoplatonic school. A century later in Alexandria the Christian John of Philoponus wrote commentaries on Aristotle, in which he took issue with Aristotle’s doctrines concerning motion. John argued that the reason bodies thrown upward do not immediately fall down is not that they are carried by the air, as Aristotle had thought, but rather that when they are thrown bodies are given some quality that keeps them moving, an anticipation of later ideas of impetus or momentum. But there were no more creative scientists or mathematicians of the caliber of Eudoxus, Aristarchus, Hipparchus, Euclid, Eratosthenes, Archimedes, Apollonius, Hero, or Ptolemy. Whether or not because of the rise of Christianity, soon even the commentators disappeared. Hypatia was killed in 415 by a mob, egged on by Bishop Cyril of Alexandria, though it is difficult to say whether this was for religious or political reasons. In 529 the emperor Justinian (who presided over the reconquest of Italy and Africa, the codification of Roman law, and the building of the great church of Santa Sophia in Constantinople) ordered the closing of the Neoplatonic Academy of Athens. On this event, though Gibbon is predisposed against Christianity, he is too eloquent not to be quoted:

The Gothic arms were less fatal to the schools of Athens than the establishment of a new religion, whose ministers superseded the exercise of reason, resolved every question by an article of faith, and condemned the infidel or skeptic to eternal flames. In many a volume of laborious controversy they espoused the weakness of the understanding and the corruption of the heart, insulted human nature in the sages of antiquity, and proscribed the spirit of philosophical inquiry, so repugnant to the doctrine, or at least to the temper, of a humble believer.14 The Greek half of the Roman Empire survived until AD 1453, but as we shall see in Chapter 9, long before then the vital center of scientific research had moved east, to Baghdad.