chapter 6 Steno’s Myology: The Right Theory at the Wrong Time

Troels Kardel

1 Introduction

The Elementorum myologiæ specimen seu musculi descriptio geometrica,1 com- pleted and published in in 1667, was the third and main work on muscle contraction by .2 It included a letter in which the author thanked his host and benefactor in Paris, Melchisédec Thévenot, for his hospi- tality and for having procured for Steno the favor and affection of his friends, including Steno’s new benefactor, the Grand Duke of Tuscany, Ferdinand ii. In the letter, Steno also told Thévenot that the reception in Florence of his “new system of muscle” had not been smooth:

There is no need to borrow arguments from Orators to prove that sweating over this work is not the doing of a man who often spends his leisure time in the presence of famous men, as my critics have not been ashamed to assert […]. It deals with the motor fibre; with the part that moves the limbs, that breathes the air, that moves the blood—in short, it deals with that upon which depend the signs of life and death. But who will call idle the desire to explore the nature of a part which, so far, remains almost unknown and see what can be accomplished by this exploration? But such considerations escape our critics. […] You as well as I remember the objection:What is the use of wanting to know?What practical application does it have? So by repeating their questions again and again, adorned

1 I use the following additional abbreviation: som = Stensen, Steno on Muscles, ed. T. Kardel, transl. M.E. Collins and P. Maquet. 2 For the three works (in order of writing), see N. Steno, Nova musculorum & cordis fabrica in Thomæ Bartholini, Epist. Medicin. Cent. iv (1667), Epist. lxx, pp. 414–421, facs. and transl. in som, pp. 58–75; De musculis & glandulis observationum specimen (1664), transl. in km, pp. 463–477; and, third and finally, Elementorum myologiæ specimen seu musculi descriptio geometrica (1667), facsimile and transl. in som, pp. 76–228.

© koninklijke brill nv, leiden, 2018 | doi: 10.1163/9789004360655_008 steno’s myology: the right theory at the wrong time 139

with various figures of speech, they try to make those who remain cease- lessly alert to new discoveries, appear ridiculous, I may even say trouble- some.3

Steno’s unnamed adversary in the Florentine was prob- ably Giovanni Alfonso Borelli, professor of at Pisa University. Steno had become the protégé of Vincenzo Viviani, another mathematician of the academy and Borelli’s arch enemy. The academy was already split into factions gathering around each of them and it dissolved shortly after.4 Borelli left Tuscany in 1667 to complete a trilogy on the physical principles of move- ment.5 In the third and best known part, De motu animalium from 1680/81, he undertook to refute Steno. What was the scientific substance and background of their conflict? Part of it concerned Borelli’s jalousy in relation to a foreign intruder who was thirty years younger than himself and who, within a year of his arrival in Tuscany, received all the attention of the Florentine academy’s leaders, including Ferdinand and his brother Leopold (later to become cardinal) and several scholars working in an area of research until then dominated by Borelli.6 If we take a closer look on their dispute, it does however also reveal incompatible ideas regarding the mechanics of muscle contraction.7 I have written elsewhere about the conflict between Steno and Borelli, in particular in my introduction to the 1994 edition of Steno’s texts entitled Steno on Muscles.8 In the following, I add some points that I have reconsidered since then, while also taking into account the work of later commentators. I will put the conflict with Borelli in the context of Steno’s early work on muscles, with particular emphasis on his opposition to Descartes. This allows me to explain in greater detail some difficult technical

3 Steno to Thévenot, [publ. 1667], transl. in som, pp. 221–223 (transl. slightly altered). The letter comprises the second part of the Elementorum myologiæ specimen. 4 See Boschiero, Experiment and natural philosophy in seventeenth-century Tuscany, pp. 37–56 (chapter on Viviani), and pp. 59–92 (chapter on Borelli). 5 See Borelli, De motu animalium, 2 vols., 1680–1681, transl. in Borelli, On the Movement of Ani- mals; Borelli, De vi percussionis, 1667, transl. in Borelli, Borelli’s On the Movement of Animals— On the Force of Percussion; and G.A. Borelli, De motionibus naturalibus a gravitate pendentibus, 1670, transl. in G.A. Borelli, Borelli’s On the Movement of Animals—On the Natural Motions Resulting from Gravity. 6 See Meli, “The Collaboration between Anatomists and Mathematicians,” pp. 665–709. 7 See Kardel, “Function and Structure in Early Modern Biomechanics,” pp. 61–70. 8 Kardel, “Stensen’s myology in historical perspective,” in som, pp. 1–57.