## 1. Life and works



Sturm was born in Hilpoltstein close to Nuremberg on November 3, 1635
in the midst of the Thirty Years War (1618-1648) which
devastated mainly those areas that were to later constitute the
territory of Germany. Sturm's father, Johann Eucharius Sturm,
was a tailor, valet, treasurer, and custodian of the silverware at the
court of Count Palatine Johann-Friedrich of Pfalz-Hilpoltstein.
Sturm's mother was Gertraud Bock, daughter of Konrad Bock,
country parson of Liebenstadt. During his infancy, Sturm learned Latin
and other (fine) arts from the court chaplain (*concionator*),
Johann Jakob Beurer.



When the Count Palatine Johann-Friedrich (himself a Protestant) died
in 1644, leaving no heir to the throne, his territory devolved unto
his older brother Wolfgang Wilhelm, who had converted to Catholicism
in 1613. Although Johann-Friedrich had reached an agreement with his
brother that (unlike all other subjects) the courtiers and servants to
Johann-Friedrich's court could remain Protestant, this promise
ceased upon his death. As a consequence of the Counter-Reformation,
all subjects had to become Catholic. Sturm and his family, being
Lutherans and resisting this call, fled the county in 1645. They
settled close by in Weissenburg. From 1646 onwards, Sturm
attended the Latin School in Weissenburg living in the house of
the rector, Johannes Hupfer, who took care of him. In 1653, upon the
advocacy of Sturm's father, Daniel Wulfer, priest and dean
of St. Lorenz, employed Johann Christoph as amanuensis. He supported
Sturm financially and furthered his academic career. Initially, Sturm
might have thought about studying at the University of Altdorf, since
he enrolled on October 4, 1653. However, he did not take up his
studies.



Instead of studying at the University of Altdorf, Sturm decided to
read at the University of Jena, enrolling on February 2, 1656. Sturm
studied mathematics and physics with both Erhard Weigel
(1625-1699) and Johann Zeisold (1599-1667). He studied
theology with Henning Spoercke. Sturm was awarded the degree of
*magister philosophiae magna cum laude* on January 27, 1658. On
October 10, 1660 Sturm enrolled at the University of Leiden, where he
studied philosophy with Johannes De Raey (1622-1702) and
architecture *privatim* with Nicolai Goldmann
(1611-1665). It was in Leiden that Sturm most likely came into
contact with the concept of and the driving force behind the idea of
eclecticism (see
 sect. 2)
 as Henricus Bornius (1617-1665), professor of ethics at the
University of Leiden, had formulated it in his (1653) inaugural
lecture *De vera philosophandi libertate.* During his one-year
stay in Leiden, Sturm also visited Baruch de Spinoza
(1632-1677). In 1661, Sturm returned to Jena via Amsterdam,
Hamburg, Lower Saxony, Magdeburg, and Leipzig. In Jena, he spent one
more year on the study of theology.



In 1662, Sturm returned to his former benefactor, Daniel Wulfer,
instructing his sons, but also conducting his own philosophical
studies. Only in 1664 was Sturm able to find a decent employment as
priest of Deiningen and (from 1667 onwards) Klosterzimmern, allowing
him to settle and start a family.



On August 15, 1669 Sturm was offered a position as professor of
mathematics and physics at the University of Altdorf, which he took
over from Abdias Trew (1597-1669). Sturm held this position
until his death in 1703. His most famous students were the Swiss
polyhistor Johann Jakob Scheuchzer (1672-1733); Johann Gabriel
Doppelmayr (1671-1750), a German mathematician, natural
philosopher and encyclopedist; Johann Heinrich Muller
(1671-1731), one of Sturm's successors to the chair of
mathematics and physics at the University of Altdorf; Martin Knorre
(1657-1699); and Georg Albrecht Hamberger (1662-1716), a
teacher of Christian Wolff (1679-1754). Besides his
professorship, Sturm was twice the rector of the University of
Altdorf, and nine times the dean of the faculty of philosophy.



Sturm was married three times: his first wife was Barbara Johanna
Kesler. They married in 1664. She died in 1679. His second wife was
Maria Salome Hochstetter. They married in 1680. She died in 1691.
His third wife was Dorothea Elisabeth Goring. They married in
1692 and she outlived Sturm. Sturm had 13 children, Leonhard Christoph
Sturm being the most famous one.



Sturm died in Altdorf on December 25, 1703 from the consequences of a
stroke he had suffered two months earlier. He was said to be 



> 
> 
> a pious, honest, kind, upright man, of clear speech, very eager in
> [the search for] justice and truth, and the successful renovator of
> mathematical studies. (Brucker 1766: 770) 
> 
> 
> 



In his eulogy on Sturm, Georg Paul Rotenbeck, who was ordinary
professor of political science and logic at the University of Altdorf
and whose daughter was married to Sturm's son Leonhard
Christoph, portrays Sturm as humble, decent, impartial, duteous,
patient, and godly. Furthermore, Sturm is venerated as a brilliant
philosopher and mathematician as well as a good family father (Hermann
& Platz 2003: 10-27).



Throughout his life as professor of mathematics and physics at the
University of Altdorf, Sturm produced a variety of works, including
mathematical textbooks, a colorful set of disputations, works on
astronomy (aimed at discrediting astrology), and calendars. However,
Sturm's core interest concerned natural philosophy. He published
three systematic treatises on physics, the *Physica
Conciliatrix* (PC, 1684), the *Physica Electiva sive
Hypothetica* (PE, 1697/1722) and the posthumously published
*Compendium Physicae Modernae Sanioris* (CPMS, 1704).



The *Physica Electiva* is Sturm's masterpiece. It is
divided into three parts: a *physica generalis* (general
physics) that lays down the foundations of Sturm's system and
includes his discussion of key metaphysical themes such as the nature
of matter, form, and causation; a *physica specialis* (special
physics) that covers the main phenomena of the supralunary and the
sublunary world; and a *physica specialissima* (very special
physics) that is devoted to the study of life and human beings. During
his life, Sturm managed to published only the *physica
generalis*. The *physica specialis* was published
posthumously by Christian Wolff in 1722. The third part has never been
published. It has been alleged that it were held in manuscript form by
the city library of Nuremberg (Gaab, in Gaab et al. 2004). Based on
archival research conducted by one of the authors (C. Henkel) in the
city library of Nuremberg in October 2019, he thinks no such
manuscript exists there. However, the city library of Nuremberg holds
what he takes to be study notes of Sturm's students on courses
in natural 
 philosophy.[1]


### 1.1 Sources of Sturm's thought



In line with his eclectic approach to philosophy (see
 sect. 2),
 Sturm surveys and builds upon a wide range of sources. They include
pre-Socratic authors, such as Thales, Pythagoras, Heraclitus,
Parmenides, Empedocles, and Democritus as well as philosophers of the
classical period, such as Hippocrates, Plato, Aristotle, Epicurus,
Euclid, and Archimedes. Due to the Aristotelian curriculum dominating
the life of early modern academic philosophers, Sturm draws upon
Aristotle (in particular his Physics) more often than upon any other
author. Furthermore, Sturm avails himself of Roman philosophers both
Stoic, such as Cicero, Seneca, Pliny the Elder, and Plutarch, and
Sceptic, such as Sextus Empiricus and Aulus Gellius. Other authors of
the era include Potamon of Alexandria, whom Sturm takes to be the
first eclectic philosopher; Galen, as well as Diogenes Laertius,
an important source for early modern philosophers to study the
philosophers of antiquity.



Furthermore, Sturm knows the Church Fathers, that is, he mentions
Clemens of Alexandria, Origen of Alexandria, and Lucius Caecilius
Firmianus Lactantius. He takes the Church Fathers to be eclectics.



Sturm is well-versed in the Aristotelian commentary tradition
including the Greek commentators rediscovered in the Renaissance
(Schmitt 1983), such as Iamblichus, Alexander of Aphrodisias,
Themistius, Ammonius Hermeae, Simplicius of Cilicia, Philoponus (John
the Grammarian), and Olympiodorus the Younger; the Arab commentators,
such as Avicenna and Averroes; as well as the Latin commentators,
such as Albertus Magnus, Thomas Aquinas, Duns Scotus, Durandus of St.
Pourcain, and William of Ockham. Following a general line of
thought manifesting itself in the Renaissance among both Aristotelian
and Humanist thinkers (Schmitt 1983), Sturm takes the Greek
commentators to be more reliable and true to the views of Aristotle
himself than the Latin commentators (PE I: preface).



Sturm draws extensively on Aristotelian thinkers ranging from medieval
scholastic authors, such as Gabriel Biel, to Renaissance and late
early modern scholastic authors. The latter include Italian
philosophers, for instance, Julius Caesar Scaliger, Andrea Caesalpino,
Jacopo Zabarella, Giulio Pace, and Francisco Lana de Terzi; Dutch
philosophers, such as Gijsbert Voet (Voetius); Spanish and Portuguese
philosophers such as Gomez de Pereira, Pedro da Fonseca,
Francisco de Toledo, Antonio Rubio, Francisco Suarez, Gabriel
Vasquez, Pedro Hurtado de Mendoza, and Rodrigo de Arriaga;
French philosophers, such as Samuel Maresius, Honore Fabri,
Jean Baptiste Du Hamel, and Pierre Daniel Huet; English philosophers,
such as John Case and Gilbert Jack (Jacchaeus); and German
Philosophers, such as Daniel Sennert, Christoph Scheibler, Johannes
Zeisold, Johann Sperling, Jakob Thomasius, and Erhard Weigel. Sturm
knows the German academic philosophical landscape very well, since
these philosophers were influential in their respective fields (see
Wundt 1938), or since they were either Sturm's colleagues or
teachers. The latter is true of Zeisold and Weigel.



In addition, Sturm is acquainted with humanist thinkers, such as
Lorenzo Valla, Juan Louis Vives, Philip Melanchthon, and Pierre de la
Ramee. Furthermore, his sources include early modern natural
philosophers: microscopists, such as Marcello Malpighi, Antonie
Philips van Leeuwenhoek, and Nehemiah Grew, but also astronomers such
as Nicolaus Copernicus, Tycho Brahe, Galileo Galilei. Sturm is also
familiar with Renaissance and early modern physicians and anatomists
such as Jean Fernel, William Harvey, Claude Perrault, and Jean
Pecquet.



Sturm is acquainted with alchemist sources, such as the *Corpus
Hermeticum*, Paracelsus, Jan Baptista van Helmont, and Athanasius
Kircher, as well as atomists such as Lucretius and Pierre Gassendi,
none of whom he looks upon very favorably.



Concerning seventeenth-century philosophers, Sturm builds upon Francis
Bacon and Gerrit Janszoon Vos (Vossius) regarding his eclectic
philosophy and scientific method. He argues against Spinoza's
and Leibniz's conception of nature, and mentions Thomas Hobbes,
Kenelm Digby, Blaise Pascal, and Isaac Newton in passing. Sturm also
argues against the Cambridge Platonists, such as Henry More and
Ralph Cudworth. In contrast, he builds upon Cartesian thought, using
Rene Descartes, Johann Clauberg, Geraud de Cordemoy,
Louis de la Forge, Antoine le Grand, and Nicolas Malebranche as 
sources.
Cordemoy, La Forge Malebranche, and the Christian mystic Pierre Poiret
inspire Sturm's case in favor of occasionalism.



Finally, Sturm corresponded extensively with members of the Royal
Society, such as John Wallis, Robert Boyle, and Robert Hooke. It is in
Boyle that he finds backup for his own position of the passivity of
nature in the controversy with Leibniz and Schelhammer (see
below).


### 1.2 Reception of Sturm in Leibniz and Wolff



Today, Sturm is most commonly remembered as the polemical target of
Leibniz's essay *De Ipsa Natura* (1698), which is part of
an articulated controversy between Sturm and Leibniz on whether nature
can be considered endowed with active principles (a claim denied by
Sturm and defended by Leibniz). In fact, Leibniz and Sturm knew of one
another, since they were both students of Erhard Weigel (Lemanski
2018). Presumably, they met in the 1660s, maybe when Leibniz was at
Altdorf University in 1666 or when he was the secretary of the
alchemical society in Nuremberg in 1667 (for Leibniz life, see Arthur
2014: x-xvi).



In his *De Ipsa Natura*, Leibniz presents Sturm as a supporter
of Malebranche's occasionalism. This charge is partially correct
insofar as Sturm does claim, like Malebranche, that God is the only
active cause operating in nature. However, Leibniz oversimplifies
Sturm's position. Sturm's account of passive forms is in
fact different from Malebranche's occasionalism for the role
that it attributes to finite forms in the explanation of natural
phenomena and for the relatively minor role that the notion of the
laws of nature plays in Sturm's account (see
 sect. 3).


 More generally, Sturm's project is diametrically opposed to
Leibniz's. At the core of Leibniz's criticisms is his
commitment to the traditional scholastic view that the notions of
substance and action are deeply interconnected (e.g. Leibniz 1989,
160). The commitment to the notion of action as the fundamental ground
to think about the very nature of substances underpins Leibniz's
main objections to Sturm's account of the passivity of
forms. Leibniz cannot accept that any natural being could ever be
adequately conceived, or taken to have any ontological consistency,
without referring to some kind of activity. However, Sturm rejects
precisely Leibniz's fundamental commitment to activity as the
ontological ground of substances. As a result, Sturm hardly offers
Leibniz any answer that would be satisfying from the latter's
point of view.



The clash of fundamental philosophical intuitions that surfaces in the
exchange between Leibniz and Sturm is particularly interesting with
regard to the complex evolution of early modern philosophy across the
seventeenth and eighteenth centuries (Sangiacomo 2020a and 2020b). In
a sense, Leibniz voices the main objection that can be raised against
Sturm; namely, without some active principle "mechanical
forms" are just idle constructions that cannot perform any
genuine explanatory role. However, Sturm's consistent way of
maintaining that explanation does *not* require any reference
to intrinsic causal powers points, in fact, to an alternative account
of causation and causal explanations altogether, which was emerging at
the time (Carraud 2002; Sangiacomo 2019, 2020c).



Despite Leibniz opposing Sturm's metaphysics and natural
philosophy, he was appreciative of and influenced by Sturm's
(and Weigel's) developments in logic (Lemanski 2018).
Furthermore, Leibniz's major disciple in Germany, Christian
Wolff, was very much fond of Sturm himself. So much so that it was
Wolff who supported the publication of the *pars specialis* of
Sturm's PE and provided a preface to it. Wolff was probably
familiar with Sturm due to Wolff's former teacher, Georg
Albrecht Hamberger, who in turn had studied with Sturm (Gaab, in Gaab
et al. 2004: 48f).



In his preface, Wolff is full of praise for Sturm, especially because
he believes to find in Sturm's method an anticipation of his own
tripartite division of knowledge into historical knowledge or
knowledge of facts, philosophical knowledge or knowledge of causes,
and mathematical knowledge or knowledge of the quantities of things
put down in the first chapter of the *Philosophia Rationalis*
(see
 SEP entry on Christian Wolff,
 sects. 3 and 7). However, Wolff is aware that mathematical
quantification does not figure in Sturm's method as prominently
as the other two types of knowledge. Besides, Wolff compliments Sturm
for establishing experimental teaching (*collegia*) -- an
academic novelty. Moreover, he looks very favorably on Sturm's
three physics, praising Sturm's scientific method
 (sect. 2),
 and pointing out the very positive reception of the first part of the
PE. He laments the absence of a third part (the *pars
specialissima*) of the PE, which was supposed to deal with living
beings. Sturm's death prevented its termination and successive
publication. However, in order to close this gap, Wolff directs the
reader to the lecture of Honore Fabri's works on plants,
animals and human beings. Indeed, Sturm himself had allegedly
recommended to the editor to join Fabri's writings on these
matters with the two completed parts of the PE to provide a complete
physics. Besides Fabri, in the preliminaries, Wolff directs the reader
to the works of Gassendi, Clauberg, Du Hamel, La Forge, Cordemoy,
Harvey, Perrault, Malpighi, Grew, and Ray to obtain knowledge about
plants, animals, and especially the connection of the mind and the
body in the human case.


## 2. The scientific method: experimental, hypothetical, eclectic



Sturm's scientific method aims at providing a complete system of
natural philosophy in which (potentially) all natural phenomena can
receive satisfying causal explanations based on available observations
and by taking into account the most perspicuous hypotheses advanced.
Sturm's method consists of three main steps, which also provide
the recurrent pattern used to discuss all topics covered in the
*Physica
 Electiva*.[2]




The first step consists in collecting phenomena, either reported by
other natural philosophers or encountered by means of observation or
experimentation itself. They need to be reported faithfully
(*fideliter*), by accurately presenting the circumstances under
which the phenomena obtained (PE I: preface, art. 3.4).



Sturm was committed to the new emerging experimental natural
philosophy and he was among the first university professors in Germany
to introduce an experimental approach on an academic level. Inspired
by the experimental method advanced by Bacon and Boyle, he offered
regular yet private experimental *collegia* (teaching). His
*Collegium experimentale sive curiosum* (1676/1685) reveals
that Sturm was familiar with the state of the art of experimental
natural science, putting to good use the new instruments available at
the time; namely, the telescope, microscope, air pump, diver's
bell, etc. Furthermore, hypotheses (the basis of theory-building) are
measured both against their congruence with phenomena and the results
of experiments. Paradigmatic experimenters for Sturm are Otto von
Guericke, Caspar Schott, and Robert Boyle.



However, Sturm does not content himself with putting forth a mere
natural history, a mere listing of things found in nature, or curious
experimental results. Natural philosophy must provide deeper causal
explanations for why the phenomena are such as they are and why they
occur. To achieve this goal, the natural philosopher should take stock
of experimental findings and available observations and investigate
suitable hypotheses to explain them.



The second step, hence, consists in collecting and presenting with the
same faithfulness old and new hypotheses that have been suggested to
account for the phenomena. Sturm meticulously presents hypotheses old
and new, from Pre-Socratic to seventeenth-century authors (see
 sect. 1.2).
 Sturm shows himself to be an assiduous, diligent reader of the
natural philosophy available at his time. His knowledge of more and
even less prominent authors is impressive and precise.



Sturm's last physics, the *Compendium Physicae Modernae
Sanioris* (CPMS), makes particularly clear that hypotheses have a
place in between observations by the senses and certainties revealed
by the demonstrative method. He points out that some things are
obvious, in that they are observed by the senses or by means of
experiments including the use of newly invented instruments (CPMS:
2f). Some things are merely conjectured rather than infallibly
demonstrated (*supponuntur verius & conjiciuntur, quam
infallibiliter demonstratur*) (CPMS: 3). Some are certain, in the
sense that phenomena and hypotheses align, that is, they are 



> 
> 
> deduced (*deducuntur*) from phenomena and hypotheses in such a
> way by means of the demonstrative method that due to the ubiquitous
> harmonizing correspondence itself of the phenomena with the
> hypotheses, by means of a certain demonstrative regress, the things
> that had been assumed in a way seemingly true
> (*verosimiliter*), ascend to (*evadent*) truth and
> certainty. (CPMS: 3f)
> 
> 
> 



The third step of Sturm's method aims at selection and
reconciliation of different hypotheses and at the final concocting of
a satisfying account of the phenomena at stake. Sturm's goal is
to distil what is good and reasonable while discarding
pseudo-explanations, prejudices and preconceived notions. This step is
approached mainly through critical investigation, rational discussion
and logical inference. In this sense, it is the more philosophical or
speculative part of Sturm's method. The goal of this third step
is thus to critically assess and integrate the hypotheses
collected.



At the beginning of his preface to the PE (PE I: art. 3.1), Sturm
(possibly inspired by Boyle and Mariotte) extensively investigates
criteria good hypotheses have to meet. They have to have a reasonable
degree of possibility and show the connection among phenomena. They
have to satisfy the circumstances that obtain. A hypothesis is better
in case it can accommodate more phenomena and notable circumstances.
Simpler hypotheses should be preferred. Hence, Sturm avails himself of
Ockham's razor in choosing among hypotheses. The reasoning
behind this is that simple hypotheses mirror God's ways which
are simple (PE I: preface, art. 3.1). God as the wisest creator of
nature (*Opificem naturae Sapientissimum*) designed the world
by simple means which have to be taken into consideration when
studying nature and its design. Furthermore, good hypotheses should
neither conflict with phenomena, other established hypotheses nor
evident principles (PE I: preface, art. 3.2). Finally, Sturm points
out that hypotheses have to satisfy not only the intellect but also
the imagination and the senses (PE I: preface, art. 3.3).
Sturm's reasoning here is that all natural phenomena are
phenomena pertaining the world of extension and its modifications like
shape and motion. The senses and the imagination are first and
foremost concerned with the realm of extended beings, and therefore to
assess the aptness of hypotheses about natural phenomena, one needs to
consult both of these faculties. Mere abstract conceptual reflection
about nature as is characteristic of the scholastics (Sturm thinks) is
not sufficient, since worldly phenomena are most proximate to and
palpable by the senses and the imagination (PE I: preface, art
3.3).



In this three-step method, the presentation of phenomena establishes
the *explanandum*, the hypotheses cover some ground towards
approximating a solution. But since these different hypotheses either
contradict or run parallel to one another, a true explanation has to
select from existing theories what is true, reject what is false, and
add what needs be added. This brings us to Sturm's
 eclecticism.[3]



The eclectic approach consists in nothing other than 



> 
> 
> to select and adopt (*sibi sumere*) from all sects of
> Philosophers that which is true, having left behind what is false and
> erroneous. (PE I: preface, art. 2.1) 
> 
> 
> 



Sturm encountered the eclectic method during his one-year stay in
Leiden in 1660 probably inspired by Henricus Bornius. Both the preface
of Sturm's *Physica Electiva* and his disputation *De
Philosophia Sectaria & Electiva* (DSE; in his 1686
*Philosophia Eclectica*) held in 1679 are pleas for
eclecticism, which contrasts sharply with sectarian philosophy.
According to Sturm, the whole of philosophers -- bracketing
sceptics and doubters (*sceptios ac dubitatores) --* can
be subsumed under two classes: sectarians and eclectics (DSE: 3).



Sectarian thinkers are led by an authority on whom they slavishly
depend. They do not follow their own reasoning, but spend their time
absorbing, reproducing and fiercely defending what they have learned
*ex cathedra.* Sectarian philosophers do not follow the truth
of what is being said, but the authority of the person who said
something. The most notable sects in Sturm's days are the
Aristotelians (*secta Aristotelica*) with its two main
branches, namely, the Greek interpreters and the scholastic
commentators; the Cartesians (*secta Cartesiana*); the
Gassendists (*secta Gassendica*) reviving Epicurean and
Democritean thought; and the Neoplatonists (*secta
Neo-Platonica*) (DSE: 13). In his *Physica Electiva*, Sturm
mentions the alchemical school (the *Spagyric* school or that
of the chemists [*Chemicorum*]) as the fourth main one omitting
Neo-Platonism (PE I: preface, art. 3.5).



The case for eclecticism is made *ex negativo* by challenging
sectarianism and positively by bringing to light the strengths of the
eclectic method. Concerning the repudiation of sectarian philosophy,
Sturm argues that adopting a sectarian approach is first of all not a
necessity (*Sectariae quippe Philosophiae primo nulla est
necessitas*). It is not the only option (see DSE: 28f). Second,
following one authority is not only not useful, it is even dangerous
and damaging to the advancement and augmentation of the sciences.



In contrast to this, eclectic philosophers are defined as:



> 
> 
> [T]hose who did not want to hang on to every word of someone, nor
> swear by the words of one master; they knew and collected for their
> storehouse everything that is true and good from the words and
> writings of whatever teachers (*Doctorum*) not convinced by the
> authority of the person teaching but by the weight of the arguments
> and demonstrations; even more they added from themselves as much as
> they could; they make it their business (*sustineant*) to see
> with their own rather than with someone else's eyes. (DSE: 3f;
> see also DSE: 6, 28)
> 
> 
> 



The eclectic method acknowledges the feebleness of the human mind, its
proclivity to err (DSE: 23). In this it is humbler than sectarian
philosophy which assumes to find all the truths in one author. Since
humans on their own tend to misjudge things or make mistakes, they
depend on one another as correctives. The scientific study of nature
if it is to succeed, hence, becomes a collective endeavor:



> 
> 
> By the name of the eclectic philosophers we understand in this whole
> treatise no others than those, who do not reject without a difference
> all the things that are found (*inventa*) and left
> (*tradita*) by the heads of different sects, and who are not so
> moved by the authority of one leader that they do accept all of his
> utterances and *bons mots* (*dicteria*), but who
> acknowledge the feebleness (*imbecillitatem*) of the human mind
> (*humani ingenii*), which makes it apparent that all depths of
> nature and reason cannot be exhausted by one or a few men; they
> persuade themselves that the truth can be only viewed in part, and
> that the sciences are to be advanced and stabilized by means of united
> powers (*junctis viribus*) and communicated advice
> (*communicato consilio*). (DSE: 7f)
> 
> 
> 



It should be stressed that although eclecticism means collecting what
is good in other authors, it does not just aim at a mere collection of
true or probable hypotheses, but instead at the formulation of a
coherent system of natural philosophy (PE I: preface, art. 3.2).
Eclecticism, in Sturm's eyes, explicitly invites the correction,
emendation and augmentation of existing theories (DSE: 48, 69). It is
a philosophical approach more useful and appropriate for the
advancement of the sciences than thinking in line with one author as
the sectarians do (DSE: 14).



Finally, Sturm's method conceives of natural philosophy as a
dynamic project in a state of constant transformation. To illustrate
this point, Sturm compares philosophy as a whole to a ship: it is
somewhat complete, though undergoing constant changes and mending.
Both philosophy and a ship in use need to be fixed from time to time.
Old, used-up parts (hypotheses in the case of philosophy, planks in
the case of the ship) have to go to be replaced by new parts fit to
allow both to advance (CPMS: 79). Philosophy is a never ending
project. It can only approximate truth, getting closer and closer. No
single natural philosopher has or could have exhausted and
sufficiently explained the phenomena obtaining in nature. Hence, what
needs to be done is to diligently assess and select what is good and
true in other philosophers, adding what needs to be added. New
phenomena are being discovered, new competing hypotheses are being
developed to explain them. They too need to be assessed. What is
reasonable remains. What is not able to stand up to the demands of a
good hypothesis will have to go. The experimental study of nature
proceeds, too. New instruments are being developed raising new
challenges to old hypotheses. The vastness of nature, the manifold of
its phenomena and the fact that causes cannot be observed but only
conjectured add to the difficulty of the natural philosopher's
task. It would indeed be temerity and arrogance to think that one has
explained all there needs to be explained in nature (CPMS: 67).
Therefore, Sturm is making a case for the open-endedness of natural
philosophy. Its goal is to know oneself, to know the world, and
ultimately to know God (PE I: preface, art. 4.5; CPMS: 8). A goal that
is not reachable within the life span of a human being, but a goal
worth striving for.


## 3. Occasionalism



In the theoretical part (*physica generalis*) of his
*Physica Electiva*, Sturm sets down the metaphysical foundations
of his system. In a nutshell, Sturm argues that the whole of nature
(human and angelic minds set aside) can be explained by two
principles: matter and its modes, which are material forms. Both these
principles are causally passive and shaped by local motion. Forms, in
particular, provide the specific reasons why certain phenomena are
produced in a certain way, but they do not include the causal powers
that bring these phenomena about. That power comes only from God, who
is the universal and omnipresent cause acting in nature. In order to
support this picture, Sturm gives a number of original twists to an
argumentative strategy already exploited by other occasionalist
authors, while providing at the same time a more eclectic and broader
rationale for endorsing an occasionalist metaphysics. To deepen
Sturm's account, three main points deserve special attention:
(1) the justification for *passive* forms as modes of matter;
(2) why God's causal power is directly needed to bring about
natural phenomena; and (3) the role that passive forms play in
scientific explanations.



(1) Early modern natural philosophers agree with their Scholastic
opponents in granting that matter is utterly passive and devoid of
efficacious causal powers. Sturm takes stock of this point, joining
Descartes and other Cartesians in defining matter in terms of pure
extension (*res extensa*) and motion as local motion. However,
early modern natural philosophers disagreed with Scholastics and among
themselves about the notion of 'form', whether there could
be any 'substantial form' and if rejecting substantial
forms would lead to discard all causal powers in finite beings.



Sturm's position in this debate is clear-cut. Sturm argues that
forms are nothing but *modes* of matter (i.e., modifications of
an extended substance), and since matter is causally passive, forms
are causally passive, too. Sturm agrees with many other early modern
anti-Scholastic philosophers in dismissing scholastic substantial
forms.



Sturm's argument for rejecting substantial forms is based on a
trilemma, according to which forms are either (i) purely material
beings, (ii) purely spiritual beings distinct from matter, or (iii) a
kind of being that is in between purely material and purely immaterial
substances.



The first option leads directly to Sturm's own view. If
substantial forms are purely material beings, they cannot be
substances in themselves because the form of a material body cannot be
another separate material body, given that forms operate in virtue of
their intimate union with the matter of the substance of which they
are the form. It follows that if substantial forms are purely
material, then they have to be conceived as modes of matter.



The second option is relevant because later scholastic authors (such
as Suarez) tended to use the rational soul as the prototype to
understand natural substantial forms as well. However, the rational
soul is a self-standing spiritual substance that can exist and be
conceived independently from the body with which it is united. This
entails that the rational soul is not the *form of the body*,
but simply a different, independent substance that is united with the
body itself. Hence (*pace* scholastics), the case of the human
rational soul *cannot* be used as a model to conceptualize
'substantial forms' in other (non-human) natural beings
(PE I: 94).



Sturm's argument against the third option of the trilemma runs
as follows. If one defines (as scholastics usually do) a substantial
form in terms of the role that the form plays in explaining and
accounting for the nature of composite beings, then what is called a
'substantial form' cannot belong to the ontological
category of a substance, but only to the category of
'relatives' or relational things. Sturm stresses that
"the entire nature of a form generally and essentially consists
of a relation" (PE I: 94). Forms are not beings in themselves,
but *ways* in which certain beings operate and undergo changes.
Against the third option of the trilemma, Sturm maintains that forms
are not the kind of being that can be conceived of or exist
independently from the being that they inform. Natural forms
*cannot* be understood as a kind of substance or being
intermediate between material and spiritual substances because forms
are *not* substances in the first place. Since natural forms
are *relational* beings they cannot be *substances*, and
thus the very idea of a 'substantial form' is a chimera, a
category mistake. The only viable option left is thus the one defended
by Sturm himself: forms are modes of matter, and since matter is
causally passive, forms are causally passive as well.



(2) This conclusion requires an account of how natural phenomena can
take place if nothing in nature is endowed with active causal powers.
According to Sturm, the origin of natural causality lies in God
himself. God is the substance defined by pure activity, and He is the
only truly efficient cause of all motion in the world:



> 
> 
> Only God's most efficacious volition is that truly acting power
> (*virtutem*), which moves while not being moved, which
> rigorously speaking moves, which moves one body by means of
> (*per*) another, which moves the whole corporeal world, its
> parts, some by means of (*per*) others, and in this way He
> brings about (*efficiat*) every one of the natural effects that
> happens in even the most remote corners of the Universe by means of
> his sole immediate power. (PE I: 164)
> 
> 
> 



God is the "requiring cause" (*causam exigentem*,
PE I: 161) of natural phenomena. This means that when God
*wants* something to happen then the effect obtains. However,
Sturm also maintains that God's will does not operate in nature
through its "absolute power" (*potentia absoluta*)
but rather by following what Sturm calls "respective or
hypothetical power" (*potentia respectiva &
hypothetica*):



> 
> 
> Here I established that God acts and operates in the whole of nature,
> not on the basis of his absolute power (which obtains whatever he
> wants without hindrances and in the most perfect way), but on the
> basis of a respective and hypothetical power, whose exercise God
> himself has (in the most free way) subordinated to certain conditions
> of matter or of the human mind. (PE I: 178)
> 
> 
> 



God did not establish to elicit effects absolutely by his mere act of
free will. Rather, God freely subordinated his own actions to the
obtainment of certain specific conditions, namely, certain states of
natural beings or of human minds. Sturm does not extensively use the
Malebranchian terminology of occasional causes, but he does explicitly
equate occasional causes with *sine quibus non* causes (PE I:
117). A *sine qua non* cause is a (counterfactually) necessary
condition for the production of a certain effect, although the
*sine qua non* cause does not truly contribute to its
production in virtue of any active power it possesses (see Sangiacomo
2019). Sturm's account of God's hypothetical power entails
that all natural forms are *sine quibus non* conditions for the
production of natural effects, in the sense that they do not
contribute in virtue of any active power they might have (since they
have none), but rather because God (freely) established to bring about
certain effects as consequences of certain modifications (i.e., forms)
of matter. Since (what Malebranche calls) 'occasional
causes' can be understood in terms of *sine qua non*
causation, and since Sturm maintains that all natural forms work as
*sine quibus non* causes of natural effects, it seems safe to
conclude that Sturm supports a version of occasionalism.



Hence, Sturm's strategy achieves its goal: matter is causally
passive, and material forms are passive as well. In order to account
for the changes observed in nature, it is necessary to locate a source
for causal activity. However, this source cannot be found anywhere in
the natural world itself. God is thus the only candidate left to
account for the causal active power needed to bring about natural
phenomena. God's power, however, is only responsible for the
fact *that* natural phenomena are brought about. The specific
reason *why* they are such and such is to be located in the
specific features of passive forms themselves. In this respect,
God's involvement in nature plays only a metaphysical grounding
function and it is not supposed to replace, but rather to justify, the
need to carefully investigate the mechanical structures of passive
forms.



Sturm's occasionalism, however, is quite peculiar, especially as
compared to Malebranche's more familiar version of
occasionalism. A crucial feature of Malebranche's occasionalism
is the role that the laws of nature play in accounting for natural
phenomena. According to him, natural beings do not have any causal
powers and can be occasions of their effects only in virtue of the
laws of nature established by God. In contrast, Sturm takes God to
establish the whole set of counterfactually necessary conditionals
that determine which effects will obtain when certain conditions are
in place in nature. These conditions are passive forms themselves,
which then play the role of *explanantia* of natural
phenomena.



(3) Sturm's account of passive forms breaks with the idea that
explanatory principles in natural philosophy must also account for the
active power that brings phenomena about. In this sense, Sturm
dismisses the idea that causal explanations must be based on active
powers intrinsic to the natural agents themselves. According to Sturm,
all phenomena are brought about by God himself. But God's power
being indifferent, differences among phenomena depend on passive
forms, which operate as *sine quibus non* conditions for their
production. This means that the *explanandum* in natural
phenomena is not the fact that something is brought about, but rather
the specific characteristics of what is brought about. God's
power explains that something (in general) is brought about, but only
passive forms explain what is brought about in particular and how. The
*explanandum* in natural phenomena is thus the specificity of
the phenomenon at stake, and the *explanans* of this phenomenon
are passive forms, which are a matter of empirical investigation.



Sturm's approach combines the strengths of both the scholastic
and seventeenth-century mechanist approach in order to remedy their
reciprocal shortcomings. Passive mechanical forms (as
Aristotelian-scholastic forms) are *particular* principles of
explanation that can be used to account for different specific
phenomena. At the same time, passive mechanical forms (as mechanical
principles) are ontologically nothing but modes of matter shaped by
motion. Passive forms are *different* among themselves but they
are all ontologically shaped by the same universal principles, which
make explanations based on passive mechanical forms *homogenous and
uniform* (from a conceptual point of view) without making them too
general and abstract.



Sturm's approach has at least two important implications: (i)
the integration of teleology and final causation in a mechanist
natural philosophy; and (ii) the marginalization of the laws of nature
therein.



Sturm is a strenuous defender of natural teleology and final causes.
In the chapter dedicated to final causes in the PE, Sturm presents to
the reader numerous phenomena which are supposed to back up or at
least make her inclined to accept the existence of teleology in nature
as well as the necessity to study it. Sturm mentions *inter
alia* bodily organs performing certain functions (the eyes are
there to see; the heart pumps blood through the body) and the
well-adaptedness of certain animals; for instance, in the case of
birds (geese, ducks, storks) their wings, the lightness of their
bones, and the possession of a certain type of beak. According to
Sturm, ends and uses are an inextricable part of the world as a whole
and of its parts (PE I: 226). Sturm's passive forms thus retain
the teleological connotation that Aristotelian forms already had,
fitting it into a mechanist picture of the universe. Forms are
structures of matter aimed at producing certain effects rather than
others. They are not only the efficient (passive) conditions for these
effects to obtain, but also the final (passive) principles that
explain them. Properly speaking, God himself, once again, is the sole
*final* cause in nature, since God is the one who designed,
planned and carried out the whole of nature as a gigantic and most
perfect clockwork.



Sturm's emphasis on forms has its counterpart in his
marginalization of the role that the laws of nature play in his
natural philosophy and in scientific explanations. Sturm puts forward
only two very general laws, one concerning the communication of motion
(PE I: 164) and the other concerning the mind-body union (PE I:
858-859). Focusing on the conservation of motion, it is
important to stress that this law is not supposed to explain what
specific features different specific bodies can have, nor does Sturm
ever suggest that the variety of finite things could follow from a
consideration of this (or any other) law alone. Rather, the law of the
conservation of the quantity of motion simply constrains the effects
of every natural phenomenon (namely, the fact that motion cannot be
dissipated during impacts but must be always conserved in the whole of
the universe). Remarkably, Sturm also mentions that this law is not
deduced *a priori* from purely metaphysical considerations (as
is the case in Descartes' deduction of conservation from the
nature of God's immutability), but rather only *a
posteriori* on the basis of empirical observations. As an
empirical regularity derived from experience, Sturm's
conservation law does not have the same strong metaphysical
connotations of Malebranche's laws of nature (which are grounded
in a consideration of God's attributes of simplicity and
wisdom), nor does it play any significant role in the explanation of
particular phenomena.