The European Career of a Scottish Mathematician and Physician

chapter 3 The European Career of a Scottish Mathematician and Physician

Pietro Daniel Omodeo

The Scottish mathematician and physician Duncan Liddel (1561–1613) was a northern-European errant scholar of the Renaissance. His name occasionally appears in research on early-modern astronomy against the background of events involving protagonists of higher calibre such as Nicolaus Copernicus and Tycho Brahe. Liddel earned this marginal notoriety unwittingly thanks to two indirect merits. Firstly, by a historical contingency: one of the very rare surviving copies of Copernicus’s manuscript known as Commentariolus (three manuscripts in all)1 was transcribed by the Scot while he was in the lands of the German Empire and was inserted in a copy of De revolutionibus he brought home with him. The volume is still housed in the University of Aberdeen and came from Marischal College, to which Liddel bequeathed it along with his entire library.2 The peripheral location of this northern university, formed in 1860 by the merger of Marischal College and King’s College, and the persever- ance of its academic tradition from the Renaissance to the present day allowed the survival of Liddel’s books, far from the convulsive historical events of a continental Europe preparing for the devastating Thirty Years War. Secondly, Liddel is sometimes mentioned in connection with the guerre des astronomes concerning the priority of the geo-heliocentric system. He was involved in this quarrel against his will. In fact, when Brahe learned that Liddel had been teaching his planetary hypotheses to students in Rostock and Helmstedt he became suspicious enough to charge him with plagiarism. He accused Liddel of spreading his own planetary theories while attributing to himself the discov- ery of the middle way between “the two chief world systems,” the Copernican and the Ptolemaic.3

1 Biskup, Regesta copernicana, 50, n. 55. 2 Aberdeen, University Library, Special Collections Centre (hereafter aulsc), coll. πf 521 Cop 22. Cf. Gingerich, An Annotated Census, I.216, 264 f. Also see Dobrzycki, “The Aberdeen Copy,” 124–127. Cf. chap. 12, 252, figure 12.7. 3 Schofield, Tychonic and Semi-Tychonic, Granada, El debate cosmológico, and Jardine and Segonds, La guerre des astronomes.

36 Omodeo

However, Liddel’s intellectual biography is interesting beyond such col- lateral matters. It is the story of a young man who, like many of his country- men, went to the continent in search of fortune and a scientific and humanistic education. Unlike most, he settled there almost permanently, in the space of 30 years carving out a successful academic career in the Protestant centers of central and northern Europe. In Frankfurt on Oder, Breslau, Rostock and Helmstedt, he came into contact with a lively academic and scientific world in which the legacies of Melanchthon and Luther, Copernicus and Ptolemy, Galen and Paracelsus met and clashed. This is the context in which he was able to acquire the famous manuscript of Copernicus and to meet and confront Brahe. In the end, he returned to his hometown, Aberdeen, where he was a patron and promoter of culture. Among other things, he provided financial support for the establishment of a chair of mathematics at Marischal College. In this way, he imported institutional innovations that he had been able to appreciate in the Melanchthonian uni- versities, where teaching of the so-called mathematical disciplines was at its height: arithmetic, Euclidean geometry, astronomy (spherical astronomy and planetary theory) and geography, to which were added trigonometry, computation of the calendar and ephemerides, and astrology. Moreover, the bequest of his library to Marischal College favoured the dissemination in Scotland of knowledge that Liddel had acquired during his long years of study and teaching abroad. These indications are sufficient to understand Liddel’s function as a go- between and mediator within a broad northern European context, establish- ing contacts and exchanges between the centers of German humanistic Protestantism and important centers of British culture. Therefore, it is worth the effort to retrace the steps of his iter studiorum, focusing on the centers with which he came into contact, the environments of which he became a part and the people whom he met and who accompanied him. This overview will allow us to identify crucial aspects of Renaissance science: the channels of commu- nication and of circulation of ideas in the late Renaissance of northern Europe, the institutions that made such exchanges possible, the scientific community involved and the dynamics of the production of knowledge.

1 An Eventful Life: The Sources

To reconstruct Liddel’s biography, it is expediant to rely mainly on two contem- porary sources. The first is a letter by the Greek scholar and humanist Johannes