It has long been argued whether or not Copernicusʼs astronomical theory was formed under the Arabic influence. In this context, one of the focal points has been a problem of whether or not Copernicus knew the device often called as the Ṭūsī-couple, and if so, when, where and how? We will limit ourselves just to this reciprocation device, and try to scrutinize Copernicusʼs own remarks and relevant arguments with the help of his disciple, Rheticus, in order to shed new light on this matter. Accordingly it is absolutely necessary to think again carefully Copernicusʼs exceptionally explicit allusion to Proclusʼs commentary on Euclid. Careful attention to the texts, both of Proclus and of Copernicus, will lead us to a new look at the moot question. Our conclusion is that the reciprocation device is well understandable in terms of the influence of Proclusʼ commentary tradition upon Copernicus which was probably prompted by Paduan Averroist astronomers, but not in terms of the influence of Marāgha School of astronomy.

Barhebraeus, one of the most significant figures in the Syriac Renaissance, who was a Syriac Orthodox prelate and polymath, and a younger contemporary of Naṣir al-Dīn al-Ṭūsī, wrote a Syriac astronomical work entitled Ascent of Mind. By comparing this work with Ṭūsīʼs hayʼa works, we notice that although Barhebraeus composed it using the structure of hayʼa works, the order of its chapters corresponds more closely to that in Zubdat al-idrāk fī hayʼat al-aflāk, a less popular Arabic hayʼa work of Ṭūsī, and, moreover, Barhebraeus did not make any reference to the Ṭūsī-couple. The reason for this peculiar selection can be found in the fact that Barhebraeus mentioned in the introduction of the Ascent Ptolemyʼs Almagest as “the most comprehensive and admirable” book, suggesting that to make his hayʼa book accord faithfully with the Almagest, he selected the Zubda since it adhered to the Ptolemaic system, and he rejected the Ṭūsī-couple because he was not interested in a concept newly added to the original content of the Almagest. From a detailed analysis of his selective editing of Ṭūsīʼs hayʼa works in the Ascent, I elucidate how different the scholarly stance of Syriac Christians towards Greek scholarship was from that of Islamic scholars.

This study searches to explore the contribution of Japanese scientist Akira Tsugita to the research in molecular biology and his determination to develop a career in Europe. In the mid twentieth century, together with Fraenkel-Conrat, and in line with Sangerʼs experiment on insulin, Tsugita determined the number of nucleotides per amino acid in the tobacco mosaic virus DNA, noting three amino acid differences. A triplet code was assumed. As a consequence, in 1961 Tsugita began his unusual Japanese‒European liaison with his attendance to the Fifth International Congress of Biochemistry in Moscow. By 1966, he defined the mechanism of frameshift mutations and the structure of the T4 phage genome working at Streisingerʼs laboratory in Cold Spring Harbor. This provided him with the opportunity of leaving for Cambridge, England, where he discussed the structure of T4 phage acridine dye mutants with Sydney Brenner. Tsugita moved to Europe, as a visiting Lecturer on leave of absence from the Osaka University at the University of Basel (1972‒78) at first, and then as part of the staff of the European Molecular Biology Laboratory in Heidelberg (1978‒1985), to establish and promote standards in DNA sequencing.