EULER, Leonhard. Harmonie entre les principes generaux de repos et de mouvement de M. de Maupertuis [with] Sur le principe de la moindre action [with] Examen de la dissertation de M. le Professeur Koenig, inseree dans les actes de Leipzig, pour le mois de mars 1751.
Berlin: Haude et Spener, 1751/1753. First edition.

First appearance of Euler’s three principle texts in the famous dispute over the principle of least action - “perhaps the ugliest of all the famous scientific disputes” (D.S.B. VII: 442). “In 1751 a sensational new argument began when S. König published some critical remarks on Maupertuis’s principle of least action (1744) and cited a letter of Leibniz in which the principle was, in König’s opinion, formulated more precisely. Submitting to Maupertuis, the Berlin Academy rose to defend him and demanded that the original of Leibniz’ letter (a copy had been sent to König from Switzerland) be presented. When it became clear that the original could not be found, Euler published, with the approval of the Academy, “Exposé concernant l’examen de la lettre de M. de Leibnitz” [in the memoires of the Berlin Academy for the year 1750] where, among other things, he declared the letter a fake. The conflict grew critical when later in the same year Voltaire published his Diatribe du docteur Akakia, médecin du pape, defending König and making laughingstocks of both Maupertuis and Euler. Frederick II rushed to the defense of Maupertuis, quarreling with his friend Voltaire and ordering the burning of the offensive pamphlet. His actions, however, did not prevent its dissemination throughout Europe. The argument touched not only on the pride of the principal participants but also on their general views: Maupertuis and, to a lesser degree, Euler interpreted the principle of least action theologically and teleologically; König was a follower of Wolff and Voltaire—the greatest ideologist of free thought” (D.S.B. IV: 471). “The quarrel occupied Koenig’s last years almost completely; moreover, he had been ill for several years before it started. Koenig emerged the moral victor from this affair, in which all the great scientists of Europe—except Maupertuis and Euler—were on his side.” (D.S.B. VII: 443). See also ‘Euler and Modern Science’, pp.189–190, citing these three papers. Eneström E197 (Harmony existing between the general principles of rest and movement by M. de Maupertuis); E198 (On the principle of least action); E199 (Examination of the dissertation of Professor Koenig inserted into the Acts of Leipzig for the month of March 1751).

In: Histoire de l'Académie Royale des Sciences et Belles-lettres de Berlin, Annee MDCCLI, 1753, pp.169-198; 199-218; 219-245 and 2 folding engraved plate, one of which is damp stained. The complete volume offered in fine contemporary half calf, some very light browning throughout, otherwise a fine and clean copy, not ex-library. 4to: 228 x 180 mm. Pp. (2), 356, 154, (2) pp. and 10 plates (2 related to the Euler papers).