赫拉克利德斯·彭提乌斯Heraclides Ponticus

赫拉克利德斯·彭提乌斯长期以来享有盛名，因为他是第一个提出太阳是太阳系中心的人，但这一点已被证明是由于对他所写内容的误解。

我们确实掌握一些关于彭提乌斯生平的细节。他的父亲名叫Euthyphron，是来自赫拉克利亚·庞提卡的一位地位显赫的富人，是这座位于黑海南岸的希腊城市最初创建者之一的后裔。彭提乌斯曾在雅典的科学院学习，并在公元前360年柏拉图第三次访问西西里期间受托掌管该学园。

虽然从某种意义上说他是柏拉图的学生，但他也曾随亚里士多德以及斯彪西波学习，后者是柏拉图的继任者，担任科学院的负责人。当Speusippus于公元前339年去世时，尽管Speusippus已选定色诺克拉底来领导科学院，但仍举行了一场选举以产生新的领导人。这是一场色诺克拉底、皮拉的梅内德谟与彭提乌斯之间的激烈角逐，但色诺克拉底仅以几票之差胜出。

此时彭提乌斯离开了雅典，回到赫拉克利亚·庞提卡。关于他去世的传说并不真的可信，但它们至少必定指向彭提乌斯是怎样一种人。据说赫拉克利亚·庞提卡遭遇了一场饥荒，彭提乌斯贿赂了派往德尔斐神谕的使者，让他们说如果彭提乌斯被授予金冠并在死后被尊为英雄，这座城市就会得救。故事说彭提乌斯在被授予金冠时死去。

也许彭提乌斯在这里笑到了最后，因为在他死后，基于对他作品的错误解读，他确实成了一位英雄。例如，托马斯·利特尔·希思[2]写道：-

彭提乌斯，柏拉图的著名学生，有明确证据表明他发现金星和水星像卫星一样绕太阳运行。他可能对更远的行星也得出了同样的结论，但这并不确定……

这一误解来自卡尔基狄乌斯在公元五世纪对柏拉图的Timaeus所作的评注。该评注（在[3]中奥托·纽格包尔的译文里）写道：-

彭提乌斯在描述金星的圆以及太阳的圆，并给这两个圆一个中心和一个平均运动时，展示了金星如何有时在太阳之上，有时在太阳之下。

T H Martin在1849年指出了这段话的意义，说金星有时在太阳之上，有时在太阳之下，清楚地意味着彭提乌斯相信它是在绕太阳运行。Schiaparelli接受了Martin的论点，并进一步声称彭提乌斯必定提出了太阳绕地球运行，但行星绕太阳运行的理论。这一理论最早由第谷·布拉赫在16世纪末提出，据我们所知，从未有希腊天文学家提出过。

奥托·纽格包尔 [3]清楚地表明，那段表明金星有时在太阳之上、有时在太阳之下的话，意味着它有时在太阳之前，有时在太阳之后。Toomer在[1]中完全同意奥托·纽格包尔的解读，但巴特尔·伦德特·范德瓦尔登曾提出过一个关于彭提乌斯的更令人惊讶的解读。巴特尔·伦德特·范德瓦尔登不是将其论证建立在Calcidius的话上，而是将Calcidius书中的一幅图解释为意味着太阳、金星和地球都绕一个共同的中心运行。

6中由巴特尔·伦德特·范德瓦尔登撰写的文章是他试图捍卫自己假说的尝试，尽管奥托·纽格包尔对情况作出了新的解释。这是一篇缺乏说服力的文章，似乎只是重复了巴特尔·伦德特·范德瓦尔登早先的假说，而没有做出任何努力来反驳奥托·纽格包尔相当简单且完全令人信服的论证。

然而，彭提乌斯仍然因一个天文学假说而享有盛名。许多资料都引用他的信念，即地球位于宇宙的中心，但它每天绕轴自转一次。当然，他是已知第一个持有这种观点的人，并因此值得高度赞扬。

关于彭提乌斯，我们确实知道得稍多一些。据说他（见[1]）：-

……穿着华丽，非常肥胖且威严，被雅典人起了个绰号叫“威严而宏伟”。

这个绰号是一个希腊语双关，把Pompikos（意为庄严而宏伟）一词替换了Pontikos（意为来自彭提乌斯的）。

除了天文学著作外，彭提乌斯还撰写了他那个时代一位主要哲学家会撰写的许多常见主题。这些主题包括伦理学、文学、修辞学、历史、政治和音乐。

Heraclides of Pontus has achieved fame for a long time as the first to propose that the sun was the centre of the solar system but this has been shown to be due to a misinterpretation of what he wrote.

We do have some details of Heraclides' life. His father was named Euthyphron, a wealthy man of high status from Heraclea Pontica, who was descended from one of the original founders of this Greek city on the south coast of the Black Sea. Heraclides attended the Academy in Athens and was left in charge of it during Plato's third visit to Sicily in 360 BC.

Although in some sense he was a pupil of Plato, he also studied with Aristotle and with Speusippus who was Plato's successor as head of the Academy. When Speusippus died in 339 BC there was an election for the new leader despite Xenocrates having been chosen to head the Academy by Speusippus. It was a close battle between Xenocrates, Menedemus of Pyrrha and Heraclides Ponticus but Xenocrates triumphed by just a few votes.

At this point Heraclides left the Athens and returned to Heraclea Pontica. Stories told of his death are not really believable yet they must at least point to the type of person that Heraclides was. It is said that Heraclea Pontica suffered a famine and Heraclides bribed the messengers sent to the Delphic oracle to say that the city would be saved if Heraclides was given a gold crown and made a hero after his death. The story relates that Heraclides died while being presented with the golden crown.

Perhaps Heraclides had the last laugh here for indeed he did become a hero after is death based on a false interpretation of his writing. For example Heath [2] writes:-

Heraclides of Pontus, Plato's famous pupil, is known on clear evidence to have discovered that Venus and Mercury revolve round the sun like satellites. He may have come to the same conclusion about the superior planets but this is not certain...

The misunderstanding comes from a commentary by Calcidius in the fifth century AD on Plato's Timaeus. This reads (in Neugebauer's translation in [3]):-

Heraclides Ponticus, when describing the circle of Venus as well as that of the sun, and giving the two circles one centre and one mean motion, showed how Venus is sometimes above, sometimes below the sun.

T H Martin, in 1849, pointed out the significance of the passage saying that Venus is sometimes above, sometimes below the sun clearly means that Heraclides believed that it was in orbit round the sun. Schiaparelli accepted Martin's argument and went further to claim that Heraclides must have proposed the theory that the sun revolves round the earth, but the planets revolve round the sun. This theory, first proposed by Tycho Brahe at the end of the 16th century, was never as far as we know put forward by a Greek astronomer.

Neugebauer [3] shows clearly that the passage indicating that Venus is sometimes above, sometimes below the sun, means that it is sometimes ahead of the sun, sometimes behind it. Toomer in [1] agrees completely with Neugebauer's interpretation but a still more amazing interpretation of Heraclides had been proposed by van der Waerden. Rather than basing his argument on Calcidius's words, van der Waerden interpreted a diagram in Calcidius to mean that the sun, Venus and the earth all revolve round a common centre.

The article [6] by van der Waerden was an attempt by him to defend his hypothesis despite the new interpretation of the situation by Neugebauer. It is an unconvincing article and it seems to only repeat van der Waerden's earlier hypothesis without making any attempt to counter the rather simple and totally convincing argument by Neugebauer.

Heraclides does, however, still have a claim to fame for an astronomical hypothesis. A number of sources quote his belief that the earth is at the centre of the universe but that it rotates on its axis once a day. Certainly he is the first known to have held this view and deserves great credit for it.

We do know a little more concerning Heraclides. He is said to have (see [1]):-

... dressed richly, was very fat and stately, and was nicknamed "stately and magnificent" by the Athenians.

This nickname is a Greek pun based on the word Pompikos (meaning stately and magnificent) replacing Pontikos (meaning from Pontus).

Apart from his writings on astronomy, Heraclides wrote on many of the usual topics that a leading philosopher of his day would have written on. These topics included ethics, literature, rhetoric, history, politics and music.