A guest post by Marco Storni.
Marco Storni writes …
Was Maupertuis an experimental philosopher? In a recent post on this blog, Peter Anstey pointed out the many ambiguities one encounters when one raises such a question. The perplexity concerns in particular the seemingly contradictory nature of Maupertuis’ contributions to the Berlin Academy: a forward-looking Newtonian in the 1730s, after he takes over the presidency of the Prussian Academy of Sciences in 1746, Maupertuis’ writings deal with stricto sensu scientific topics no more. Although an Experimental Philosophy and a Mathematics class existed in the Berlin Academy, “Maupertuis didn’t publish a single article in the Experimental Philosophy memoirs […] nor did he publish anything in the Mathematics section” (Anstey, The Ambiguous Status of Maupertuis), but only in the memoirs for Speculative Philosophy. This remark can be further generalized for, after 1746, also Maupertuis’ non-academic writings also deal with non-scientific subjects, including theodicy, the origin of language, and ethics. How can we explain such a change of perspective?
To answer these questions, it is necessary to understand what Maupertuis actually means by “experimental philosophy” and “speculative philosophy”. A key text is the academic address Des devoirs de l’académicien (1750), where Maupertuis discusses one by one the nature and the tasks of the Berlin Academy classes. Whereas experimental philosophy, Maupertuis says, studies natural bodies with all their sensible properties, and mathematics deals with bodies “deprived of the large majority of those properties” (Les œuvres de Maupertuis (ed. 1768), 3, p. 293), speculative philosophy is rather concerned with all the objects that have no sensible properties. In this sense,
The Supreme Being, the human soul, and everything relating the mind are the object of this science. The nature of bodies too, as they are represented in our perceptions, even if they are something else than these very perceptions, falls within its scope (Ibid., p. 293-294).
Speculative philosophy is thus concerned with all the areas experimental philosophy and mathematics do not cover. In fact, speculative philosophy studies the very same objects experimental philosophy and mathematics are concerned with (e.g., natural bodies), but from a different perspective (in the case of natural bodies, from the perspective of the experience of such bodies). Therefore, in Maupertuis’ view, speculative philosophy and experimental philosophy are not necessarily opposed but rather complementary. This is well displayed in his studies on the principle of least action, first formulated as a physical principle (in the academic paper Accord de différentes lois de la nature qui avaient jusqu’ici paru incompatibles, 1744), and then given a metaphysical interpretation (in the Essai de cosmologie, 1750).
Maupertuis says something more on the relationship between “speculative philosophy” and “experimental philosophy” in another text of the 1750s, namely the Lettre sur le progrès des sciences (1752). Here, Maupertuis introduces the notion of “metaphysical experience” that turns out to be interesting for our present concern. If physical experiences have to do with bodies—and in the first half of his career Maupertuis focused on physical experiences—metaphysical experiences deal with the spiritual world. Would it not be possible, Maupertuis asks himself, to operate on the soul by means of physiological modifications on the brain? Likewise, would it not be possible to find out how languages are formed by isolating some children and seeing how they manage to communicate? However quaint all this might seem, it nonetheless indicates that speculative philosophy is for Maupertuis essentially intertwined with experimental philosophy. Ultimately, a large part of Maupertuis’ activity in Berlin might be described as the attempt to construct an “experimental metaphysics”.
On my analysis, Maupertuis’ status as an experimental philosopher turns out to be less ambiguous than it might prima facie seem. In fact, according to Maupertuis, “over so many centuries […] our metaphysical knowledge has made no progress” (Les œuvres de Maupertuis, 2, p. 430) precisely because the method of speculative philosophy was too abstract and arbitrary. Grounding metaphysics on experiences, as he argues, might actually help to stimulate such progress: and this is the objective Maupertuis strives for in his works of speculative philosophy. On the whole, therefore, I incline to read Maupertuis’ mature position as the attempt to reform speculative philosophy out of an experimental approach. I would nonetheless be glad to hear other thoughts on Maupertuis’ experimentalism.