Er war einst groß in Spiel mit den Symbolen,
War viele Künste, viele Sprachen Meister,
War ein weltkundiger, ein weit gereister,
Berühmter Mann, gekannt bis zu den Polen,
Umgeben stets von Schülern und Kollegen.
Ein Fragment von den Gedichten des jungen Josef K.
In my blog anniversary post yesterday I explained how I came to live in Germany; today in what is a sort of continuation of that post, I will explain how I came to evolve from a rank amateur deeply interested in the histories of mathematics and science into a full blown quasi-professional historian of science. This post is a tribute to the man who is responsible for that evolution, my friend, mentor and teacher Christian Thiel, who celebrates his eightieth birthday today.
I tell a joke that when I first came to Germany I could only speak six words of German: ja, nein, bitte, danke, Bier and Scheiße. In reality this was almost the truth, so the first task I set myself, when I decided to stay, was to learn the language. As well as buying teach-yourself books, I also started attending German courses at the adult education evening classes in Nürnberg. These were actually very good but were, as far as I was concerned, far too slow and so I began to look around for alternatives. Somebody told me that the local university in Erlangen ran courses in German as a foreign language, so I trundled off to investigate. It turned out that to register for these courses I needed to apply for a place as a normal student at the university. Now I had dropped out of university in Cardiff ten years earlier, with the intention of returning to higher education when I had sorted out what it was that I really wanted to study, so I thought why not. I registered to become a maths student and was thus admitted to the German as a foreign language course.
I now spent a year learning German at the university in the mornings and working as an industrial cleaner in the afternoons. The course was very intensive, as the students are expected to be capable of taking a degree course in any academic subject in German at the end of it. To my own surprise I passed the course with flying colours and was now qualified to start my studies as a student of mathematics.
In those days the first degree in mathematics at the university of Erlangen was a diploma, equivalent of a master’s degree at an English university. Alongside the main subject students had to choose a subsidiary subject. In the 1970s I had become very interested in the philosophy of science and so I thought I would take a shot at that. One chair in the philosophy department was also offering a seminar in constructive geometry for the coming semester. I had no idea what constructive geometry was but it was an added incentive to choose philosophy as my subsidiary. The chair in question was one specialising in history and philosophy of science; I decided to go take a look see.
I found out when the professor held his office hours and went along at the appointed time. He wasn’t there. Knocking on his secretary’s door I asked when the professor would be there. She very kindly rang the professor and said that if I could wait, he would be along soon. I had waited maybe a quarter of an hour when I then met Christian Thiel for the first time. What I didn’t know was that it was not only my first semester as a student at the university but it was also Christian Thiel’s first semester as occupant of that chair. He, an Erlanger, had studied in Erlangen, taken his doctorate and his habilitation there but had then gone away to a chair elsewhere, as was normal in the German academic system. He was now returning to Erlangen to occupy the chair of his own mentor, Paul Lorenzen. What I also didn’t know at the time was that the department secretary had warned Christian Thiel that there was a ‘dangerous looking man’ waiting to see him. I was wearing a complete set of black motorcycle leathers, had my long hair tied back in a ponytail and sported three very prominent silver earrings, dangerous?
Christian Thiel wasn’t at all fazed by my dangerous appearance. We got on from the very first moment and were soon deep in a conversation about maths and the philosophy of science. In the time (ten years!) that I spent studying at Erlangen University more than fifty per cent of the courses that I took were with Christian Thiel. I think I learnt more from him than all of the other teachers that I have had in my life put together. He formed me, any abilities that I might possess as a historian of science I owe largely to Christian Thiel.
The maths department in Erlangen, when I studied, was not interested in the history of mathematics, my main motivation for studying the subject, Christian Thiel, however, was a historian of mathematics and mathematical logic, so after a time I dropped maths and became a student of philosophy with English philology and history as my subsidiaries. This move was also motivated by the fact that very early in my studies Christian Thiel, who obviously saw something in me that I couldn’t see in myself, offered me, to my surprise, a position in a major research project into the social history (read external history) of formal logic. I learnt so much in that research project, probably more than in my official studies and it is here that I really became a genuine historian of science. I can’t say how much being offered that chance, as a student, to do real cutting edge historical research meant to me. Without it I would not be sitting here now writing this blog post.
As the title of this blog post says, ‘one man takes the credit, one man takes the blame’ and that man is Christian Thiel and I am very pleased to be able to write this brief tribute to him on my blog on the occasion of his eightieth birthday.
I should point out that this is not the first tribute that I have written to Christian Thiel. The German quote that opens this post is taken from my essay in the Festschrift published in honour of his retirement twelve years ago. This in turn is loosely based on the speech I held at the conference in his honour in Altdorf in 2005. Nearly all of the lectures at the conference related to Christian Thiel as an academic researcher, I had the privilege of honouring Christian Thiel the teacher. There is not a little irony in this. Over the years Christian Thiel has taught many, many successful students, postgraduates and postdocs, I, however, am, so to speak, one of his failures, falling at the final fence and failing to graduate. I closed my speech and my essay with a simple phrase, which I’m going to repeat once again here.
“Thanks Chris, you have been a bloody good teacher.”
 A couple of words about the title and the opening quote to this post. The title is a line from Tom Lehrer’s song Lobachevsky. I would like to point out that whilst the title hero of the song has inspired the narrator to plagiarise, Christian Thiel actually taught me and all of his students the exact opposite. I chose the quote because a love of Tom Lehrer and of Hermann Hesse the source of the opening quote are two of the many things that I and Christian Thiel have in common. Das Glasperlenspiel, the source of the opening quote, is my favourite novel and when I set out to learn German, one of my aims was to be able to read it in German one day. In Germany to become a professor a scholar has to do a sort of second doctorate called a habilitation. When the habilitation thesis has been graded and accepted the potential habilitant then has to hold a habilitation lecture in front of an audience of all of the habilitanten of his faculty. Thiel’s habilitation lecture was on Das Glasperlenspiel.
 Thony Christie, The Teacher in G. Löffladt (Hrsg), Mathematik – Logik – Philosophie: Ideen und ihre historischen Wechselwirkungen, Verlag Harri Deutsch, Frankfurt am Main, 2012