I reconstruct J. H. Lambert’s views on how practical grounds relate to epistemic features, such as certainty. I argue, first, that Lambert’s account of moral certainty does not involve any distinctively practical influence on theoretical belief. However, it does present an interesting form of fallibilism about justification as well as a denial of a tight link between knowledge and action. Second, I argue that for Lambert, the persistence principle that underwrites induction is supported by practical reasons to believe; this indicates (...) that Lambert is a moderate pragmatist about reasons for theoretical belief. (shrink)

Taken together with my previous articles [77], [80] devoted to the history of finite random sums and to Laplace's theory of errors, this paper sheds sufficient light on the whole work of Laplace in probability. Laplace's theory of probability is subdivided into theory of probability proper, limit theorems and mathematical statistics (not yet distinguished as a separate entity). I maintain that in its very design Laplace's theory of probability is a discipline pertaining to natural science rather than to mathematics. I (...) maintain also the idea that the so-called Laplacian determinism was no hindrance to applications of his theory of probability to natural science and that one of his utterances in this connection could have well been made by Maxwell's contemporaries. Two possible reasons why the theory of probability stagnated after Laplace's work are singled out: the absence of new fields of application and, also, the insufficient level of mathematical abstraction used by Laplace. For all his achievements, I reach the general conclusion that he did not originate the theory of probability as it is now known. (shrink)

(2003). Fitting Geomagnetic Fields before the Invention of Least Squares: II. William Whiston's Isoclinic Maps of Southern England (1719 and 1721) Annals of Science: Vol. 60, No. 1, pp. 63-84.

The London mathematical practitioner Henry Bond correctly forecast in The Sea-Mans Kalendar for 1636 [?1638] that the then easterly magnetic declination in London would become zero in 1657 and would then increase westerly for 'at least 30 years'. In 1668, he published a table of predicted changes in annual declination for the years 1668-1716. Despite a detailed examination of his later claim to be able to determine longitude using a dip needle, the basis for his earlier forecasts was not examined (...) and Bond himself appears never to have fully revealed his methods. It is demonstrated that Bond's predictions of 1636 and 1668 are consistent with the fitting of quadratic and cubic equations to existing observational data by means of the solution of simultaneous equations, and it is therefore argued that he anticipated 'Meyer's method' by over 100 years. Furthermore, Bond's forecast of 1668 made use of his discovery that the tangent of the angle of inclination is equal to twice the cotangent of the angle of magnetic latitude, thereby anticipating the findings of Biot and Krafft by c . 130 years. (shrink)

ArgumentJohann Heinrich Lambert (1728–1777) developed a very detailed theory of science and experiment. Using Lambert's hygrometric studies, this article provides an introduction to Lambert's theory and its practice. Of special interest is his well-founded theory on the emergence and definition of concepts and his neat eye for heuristics that should ultimately lead to a mathematization of physical phenomena. His use of visualizations in this context is especially remarkable.