Back in Paris, Maupertuis was appointed assistant director of the Académie des Sciences

Back in Paris, Maupertuis was appointed assistant director of the Académie des Sciences

Back in Paris, Maupertuis was appointed assistant manager of this Académie des Sciences and in the following year be turned into its director. On 27 June 1743 he had been admitted to the Académie Française. From the autumn of 1744 he moved to Basle, and from there he travelled into the French camp in the siege of Freiburg im Breisgau. He then went back to Prussia taking with him news of the French victory which he delivered into Frederick. The Berlin Academy was now taking shape and Frederick again pressed Maupertuis to become its first president. He made a decision to take the position and returned to Paris in the spring of 1745 to clean up his affairs before taking up his new role. While in Berlin he had arranged a marriage to Eleonor Borck and, following his short visit to Paris, he married her in Berlin on 25 August 1745.

Maupertuis had committed himself to Berlin, and the Paris Academy cancelled his membership at September 1745 after a campaign against him headed by Jacques Cassini. On 12 May 1746 Maupertuis was appointed as president of the Berlin Academy, a post he was to hold for eight decades. His presidency failed to get off to a good start, however, for in June his dad died and he returned to Paris, remaining there until September. Although he tried very hard to make a success of his job as president of their Berlin Academy, things were rather against him. On the one hand he did not speak German, and even though the official company of the Academy was conducted in Latin or French, Maupertuis was cut away by the day to day government that was conducted in German. His other problem was that Frederick desired his Academy to be world class, but he wasn't prepared to set up the required capital to attract the very best men and women. Maupertuis tried to overcome it by making appointments of foreigner scientists as associate members who didn't work at the Academy. Of course the Academy did comprise one person of the very highest calibre, namely Euler.

We have mentioned a few of his gifts above, but let us now mention a few others. One important publication on natural history was Vénus physique Ⓣ at 1745 where he discussed the biological theory of the formation of the embryo. This work, along with other work by Maupertuis on heredity, suggested a set of conjectures that some view as an early version of the concept of evolution. Indeed if he'd taken his conjectures ahead and developed them into a more fully formed theory he would now be recognized as putting forward the bases of the concept of evolution. As it had been, although he put forward the mechanism to get one species developing into another, he failed to postulate the driving mechanism, especially natural choice.

We have left late in this informative article a discussion of this subject for which Maupertuis is best known, especially the Principle of Least Action. 1 reason is that indeed it had been late in his profession that he proposed the principle. It was in 1746, shortly after becoming manager of the Berlin Academy, that he first enunciated the Rule of Least Action and it was four years later that he printed it in Essai de cosmologie Ⓣ. Maupertuis hoped that the principle could unify the laws of the world and united with an attempted proof of the presence of God. He wrote (see for example [1]):-

The laws of movement thus deduced [in the Rule of Least Action], being discovered to be precisely the same as the ones seen in nature, we could respect the application of it to all phenomena, in the motion of animals, in the plant of plants, in the revolution of the heavenly bodies: as well as the spectacle of the world gets much that the grander, so much the more beautiful, so much more worthy of its Author...

All these laws, so lovely and so easy, are maybe the only ones which the Creator and Organizer of matters has established in matter in order to effect all the phenomena of the visible world...

Still another reason for leaving a discussion of the Principle of Least Action to now is that it played a huge role in the sad events close to the end of his lifetime.

Samuel König was a mathematician whom Maupertuis had known for a very long moment. Both had been students of Johann Bernoulli, both had taught du Châtelet, both'd researched the shape of the Earth, and Maupertuis had suggested Samuel König for election to the Berlin Academy. The odd affair began in 1751 when König seen Berlin and gave a paper to Maupertuis to be considered for publication. Certainly Maupertuis never see it, but only returned it the next day advocating publication. It was indeed published in March 1751 and then did Maupertuis examine it and find that on the 1 hand it contended that the Principle of Least Action was untrue, on the other hand it argued that Leibniz was the first to suggest the theory. The evidence that was put forward to support the claim was a letter of 1707 from Leibniz to Jacob Hermann.

It is fair to say that by this time Maupertuis had serious health problems. Also he never responded well to criticism, becoming more sensitive as his health declined, and we've already described the vicious personal attacks he made on his opponents in the argument about the form of the Earth several years before. However, perhaps most applicable importantly, he felt that the Principle of Least Action was his greatest accomplishment, the one for which he'd go down in history. Maupertuis was defended by Euler however he used his position as director of the Academy to get it announce publicly that König had forged the quotation. This abandoned König no option but to resign from the Academy. Voltaire had at one time been a close friend of Maupertuis, but the two had fallen out years before this sad affair. Frederick tried to encourage the president of his Academy, but Maupertuis's failing health collapsed under the strain and that he left Berlin for Paris in 1753. He stayed there for over a year, being pushed by Frederick to return to Berlin who claimed the Academy was out of control now its director was absent. This Maupertuis failed in 1754 but then he had been seemingly blackmailed by a girl who claimed he was the father of her child.

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