巴斯的阿德拉德Adelard of Bath

关于巴斯的阿德拉德的生平，鲜有细节确凿可知。我们确实知道他曾求学于法国中西部卢瓦尔河谷的图尔，后来在法国北部皮卡第地区的拉昂任教。拉昂位于兰斯西北、巴黎东北。巴斯的阿德拉德可能曾在当地的神学与释经学校任教，该校由拉昂的安瑟伦约于1100年创立。

离开拉昂后，巴斯的阿德拉德旅行了大约七年，首先访问了那不勒斯东南的萨莱诺。萨莱诺的医学院被许多人视为欧洲第一所“现代”大学，当时是一所著名机构，吸引来自全欧洲的学生。从萨莱诺，巴斯的阿德拉德前往西西里，当时该地处于诺曼人控制之下，但仍深受阿拉伯传统影响。来自北非的阿拉伯人于965年征服该岛并控制了约100年，但诺曼人于1060年夺取了该岛。

巴斯的阿德拉德接下来访问了西里西亚的辛普利修斯，这是安纳托利亚南部的一个古老地区，今属土耳其。西里西亚的辛普利修斯位于地中海东北海岸，巴斯的阿德拉德沿天然海岸路线绕过地中海东端前往叙利亚，后来又前往巴勒斯坦。我们知道他回到了巴斯的阿德拉德，并在该城1130年的记录中被提及。没有记录表明巴斯的阿德拉德访问过西班牙，但许多学者推断他必定访问过该国，才能接触到他所翻译的西班牙-阿拉伯文本。

当然，巴斯的阿德拉德成为了阿拉伯语的专家，他可能在西班牙学会了阿拉伯语，就像几年后克雷莫纳的克雷莫纳的杰拉德一样。然而，有另一种理论认为他是在西西里学会阿拉伯语的。如果情况如此，那么他很可能是在西西里接触到了西班牙-阿拉伯文本，因为当时有几位曾在西班牙生活过的学者正在西西里。

巴斯的阿德拉德写了许多关于哲学的原创著作。已知他写的第一部作品是一部哲学文本，写于1116年之前，献给锡拉库萨主教威廉。由于锡拉库萨是古代西西里最重要的城市之一，这部作品很可能是在巴斯的阿德拉德访问该岛前后写成的。然而，由于这部作品牢固地基于柏拉图的哲学，没有任何阿拉伯影响的迹象，它可能主要是在巴斯的阿德拉德的访问使他接触到阿拉伯学问之前写成的。

巴斯的阿德拉德值得被纳入这个档案，并不是作为哲学家。而是因为他是[1]：-

...将阿拉伯-希腊学术从阿拉伯语整体翻译成拉丁语的翻译者之一。

巴斯的阿德拉德从阿拉伯语来源翻译了欧几里得的Elements，这些译本几个世纪以来一直是西方的主要几何教科书。事实上，似乎有三本独立的欧几里得的Elements版本由巴斯的阿德拉德撰写。第一版是全部十五卷的翻译（欧几里得所写的13卷原著和Hypsicles所写的另外两卷）。巴斯的阿德拉德似乎以al-Hajjaj从希腊语翻译的阿拉伯语译本之一作为他的来源。

巴斯的阿德拉德所译的欧几里得的Elements第二版相当不同。它的命题陈述措辞与第一版完全不同，而证明往往只是提纲或对如何构造证明的提示。翻译的风格告诉专家们，巴斯的阿德拉德并不是从他自己的第一版产生这个版本的，而是使用了某种不同于al-Hajjaj译本的未知阿拉伯语来源。

关于归于巴斯的阿德拉德名下的欧几里得的Elements第三版是否确实是他的作品，存在争议。它是对欧几里得的Elements的评注，而不是对原文的翻译。我们知道它写于1200年之前，并以巴斯的阿德拉德的名字而广为人知。罗吉尔·培根在他的著作中引用了这个版本的内容。

巴斯的阿德拉德还翻译了花拉子米的表格，撰写了关于算盘和星盘的著作。我们应当对他翻译花拉子米的表格再作一些评论，这些表格成为第一套阿拉伯类型的拉丁天文学表格，带有希腊影响和印度符号。这些表格在第4章末尾包含了1126年1月26日这个日期（至少阿拉伯日期A.H. 520 Muharram 1对应的就是这个日期）。很难看出这个日期出现在那里是为了什么，除非它是该章完成的日期，因此它被当作巴斯的阿德拉德翻译的大致日期。然而，有一份手稿（后来写成，但是巴斯的阿德拉德译本的抄本）提到了1133年发生的一次日食。有可能巴斯的阿德拉德的翻译发生在1133年之后，或者同样可能的是，制作后来抄本的抄写员添加了关于最近一次日食的信息，而这一信息并不在巴斯的阿德拉德的原始文本中。

巴斯的阿德拉德也写过算术书，其中最早的一本写于他学习阿拉伯算术之前。它以波爱修斯的著作为基础。一部深受阿拉伯思想影响的数学论著被归于巴斯的阿德拉德名下，尽管这一归属并不确定。该著作由五卷组成，前三卷论算术，基于阿拉伯著作中所呈现的印度方法。有人推测这几卷以花拉子米的一部现已失传的算术书为基础。构成该论著的五卷中余下的两卷涵盖几何——其风格完全是希腊式的——音乐和天文学。天文学与算术一样，是阿拉伯风格的。

巴斯的阿德拉德的Quaestiones naturalesⓉ（自然问题）包含76篇基于阿拉伯科学的科学讨论。在这部著作中，他推动了实验数据的使用，并写道他[1]：-

……更偏好理性而非权威。

Few details of Adelard's life are known with certainty. We do know that he studied in Tours in the Loire Valley in west central France and that he later taught at Laon in the Picardie region of northern France. Laon lies northwest of Reims and northeast of Paris. Adelard may have taught at the theological and exegetical school there which had been founded by Anselm of Laon in about 1100.

After leaving Laon, Adelard travelled for about seven years visiting first Salerno southeast of Naples. The medical school at Salerno, considered by many to be the first "modern" European university, was a famous institution at this time, drawing students from all over Europe. From Salerno Adelard travelled to Sicily which at that time was under Norman control but still strongly influenced by Arabic traditions. The Arabs from North Africa had conquered the island in 965 and remained in control for about 100 years but the Normans gained the island in 1060.

Adelard next visited Cilicia, an ancient district of southern Anatolia which today is in Turkey. Cilicia was on the north east coast of the Mediterranean Sea and Adelard took the natural coastal route round the east end of the Mediterranean to Syria and then later to Palestine. We know that he returned to Bath and is mentioned in the records of that city for the year 1130. There is no record of Adelard visiting Spain, but many scholars have concluded that he must have visited that country to have had access to the Spanish-Arabic texts which he translated.

Certainly Adelard became an expert in the Arabic language which he might have learnt in Spain as did Gherard of Cremona a few years later. However, there is an alternative theory that he learnt Arabic in Sicily. It is quite possible that, if this were the case, then he came in contact with Spanish-Arabic texts in Sicily for several scholars who had lived in Spain were at this time in Sicily.

Adelard wrote a number of original works on philosophy. The first work that he is known to have written is a philosophy text written before 1116 and dedicated to William, Bishop of Syracuse. Since Syracuse was one of the most important cities of ancient Sicily, this work is likely to have been written around the time of Adelard's visit to that island. However, since the work is based firmly on Plato's philosophy, without any signs of Arabic influences, it may have been mostly written before Adelard's visits brought him in contact with the learning of the Arabs.

It is not as a philosopher that Adelard merits inclusion in this archive. Rather it is because he is [1]:-

... one of the translators who made the first wholesale conversion of Arabo-Greek learning from Arabic into Latin.

Adelard made Latin translations of Euclid's Elements from Arabic sources which were for centuries the chief geometry textbooks in the West. In fact there seem to have been three separate versions of Euclid's Elements written by Adelard. Version one is a translation of the whole fifteen books (the 13 original books written by Euclid and the two further books written by Hypsicles). Adelard seems to have taken as his source one of al-Hajjaj's Arabic translations from Greek.

The second version of Euclid's Elements by Adelard is quite different. It contains quite different wording of the statements of the propositions to that of version one, while the proofs are often only outlines or indications of how proofs might be constructed. The style of the translation tells experts that Adelard did not produce this from his own version one, but rather that he used some unknown Arabic source different from al-Hajjaj's translations.

There is debate as to whether the third version of Euclid's Elements attributed to Adelard is indeed his work. It is a commentary on Euclid's Elements rather than a translation of the original text. We know it was written before 1200 and became quite well known under Adelard's name. Roger Bacon gives quotes from this version in his works.

Adelard also translated al-Khwarizmi's tables, wrote on the abacus and on the astrolabe. We should make some further comments on his translation of al-Khwarizmi's tables which became the first Latin astronomical tables of the Arabic type with their Greek influences and Indian symbols. These tables contain, at the end of chapter 4, the date of 26 January 1126 (at least that is what the Arabic date of A.H. 520 Muharram 1 corresponds to). It is hard to see what this date is there for unless it is the date when the chapter was completed, and so it has been taken as the approximate date for Adelard's translation. However, there is a manuscript (written later but a copy of Adelard's translation) which mentions an eclipse of the sun which took place in 1133. It is possible that Adelard's translation took place after 1133 or, equally likely, that the scribe making the later copy added information about a recent eclipse which was not in Adelard's original text.

Adelard also wrote arithmetic books, the earliest one of which was written before he studied Arabic arithmetic. It is based on the work of Boethius. A mathematics treatise which is strongly influenced by Arabic ideas has been attributed to Adelard although the attribution is not certain. The work consists of five books, the first three of which are on arithmetic and based on the Indian methods as presented in Arab writings. It has been conjectured that these books are based on an arithmetic book by al-Khwarizmi which is now lost. The remaining two books of the five which compose the treatise cover geometry, which is completely Greek in style, music, and astronomy. The astronomy, like the arithmetic, is Arabic in style.

Adelard's Quaestiones naturales Ⓣ consists of 76 scientific discussions based on Arabic science. In this work he promoted the use of experimental data and writes that he [1]:-

... prefers reason to authority.