Gottlob Frege. Life -- work -- time (Q2718878)

This long-awaited book gives the first full-scale biography of Gottlob Frege, and brings the paradoxical situation to an end that up to now no reliable biographical information was available for one of the most important founding fathers of mathematical logic and analytical philosophy.NEWLINENEWLINENEWLINEFrege's scientific and personal estate is lost, most probably destroyed during the 1944 bomb attacks on Münster. The author had to face, therefore, a challenging task, mastered by a year-long search for traces in church books, state, university and school archives, and by discovering and interviewing members of Frege's family and eye-witnesses. These data on Frege's family background, his school days, university studies and his ``university career'' are integrated into the broader historical and social context, such as the history of his birth-town Wismar, and the development of the small University of Jena, thereby providing an almost complete history of the Jena mathematics department during the time of Frege's membership.NEWLINENEWLINENEWLINEIn the breadth of presentation the main figure sometimes seems to be pushed into the background, but the return is substantial. The author gives deep insights into the federal structure of the German university system, clarifying, besides other things, the status of academic titles like Frege's ``Honorarprofessor''. The presentation of the intellectual life in Jena shows that he was not that isolated figure as he is generally seen, and it provides furthermore access to the unwanted Frege, the writer of the notorious diary of 1924.NEWLINENEWLINENEWLINEThe third chapter is devoted to ``Number and Extension of Concept'', key concepts for Frege's early logical creative period. The guiding question is, what could have inspired and influenced Frege's stroke of a genius of his new logic? In absence of direct evidence the author applied what he called an ``hermeneutical'' method, asking what could Frege have known of contemporary work in the foundations of mathematics, and are there similarities in theory and presentation to these precursors. Candidates discussed are \textit{R. Grassmann}'s doctrine of quantities, being temporally very close to Frege's ``Begriffsschrift'', but also ``in its logical presentation of pure mathematics'' (p. 137). Frege's concept script itself is compared to \textit{K. C. F. Krause}'s and \textit{C. Fortlage}'s pasigraphies, the latter a friend of Frege's teacher \textit{C. Snell}. In a further section the author shows that some of Frege's key ideas in epistemology and the philosophy of language like the context principle might have been influenced by his father \textit{K. A. Frege} who anticipated these ideas in his ``Aid-book for the German language education for 9 to 13 years old children'' (\(^31862\)).NEWLINENEWLINENEWLINEIt is a matter of course that these considerations are not free of speculation, and not always beyond doubt. Concerning Grassmann it is claimed, e.g., that his theory should be classified as belonging to the algebraic theory of rings and fields, thus showing an essential difference to the algebra of logic which is a lattice theory using two connective operations (p. 137). This remark was obviously thought to maintain the difference between Fregean Logicism and Boole-Peirce-Schröderian Algebra of Logic. But, Grassmann uses with ``Fügung'' and ``Webung'' two connective operations, and his algebraic-logical theory was the main source of inspiration for \textit{E. Schröder}'s algebra of logic. This can be proved by direct evidence.NEWLINENEWLINENEWLINENevertheless, the book under review is the biography everyone has to consult if interested in Frege's life and the context of his work. In addition it provides deep insights into German intellectual and scientific life between 1850 and 1930.