Science in Context 25 (2012): 503–523.

Julius Caesar Scaliger on Plants, Species, and the

Ordained Power of God

Andreas Blank

1. Introduction

Up to the time around 1670, the natural philosophy of the Agen-based

physician and philosopher Julius Caesar Scaliger (1484–1558) was a

constant point of reference both in works in the Aristotelian

tradition and in works developing a mechanistic view of nature. On

first sight, the presence of aspects of Scaliger’s thought in such

diverging contexts seems puzzling. Scaliger’s commentaries on The-

ophrastus’s Historia plantarum and De causis plantarum and the Pseudo-

Aristotelian De plantis1 and his Exotericae exercitationes, a 1000-page

response to Girolamo Cardano’s De subtilitate, strike the reader as

fragmentary and chaotically organized, deeply imbued in philological

reasoning, and remarkably disinterested in new observational data.

Yet, as seminal studies by Norma Emerton and Christoph Lüthy have

brought to light, Scaliger’s writings on natural philosophy are

interspersed with numerous innovative ideas that proved to be

1

influential in the development of early modern corpuscularian matter

theories.2 In what follows, I will examine one of Scaliger’s

innovative ideas in natural philosophy—the view that in singular

cases the occurrence of new plant species is a genuine possibility3—

and discuss a tension that seems to arise between this idea and some

of Scaliger’s (also quite innovative) ideas in philosophical

theology—in particular, his view that the ordained power of God is

bound to chose to create the best possible world.4

To be sure, Scaliger does not plunge all at once into a modern

conception of species, nor does he believe that any species could

develop into another species. In fact, he explicitly denies the

latter claim5 and endorses an essentialist conception of species—the

view that essences define species membership6. Still, his view

departs from the doctrine of species fixism—the view that no new

species can come into being—that was universally accepted by his

contemporaries. Contrary to species fixism, he holds that living

beings can come into existence that belong to species that did not

exist before. Yet, this claim seems to be in tension with Scaliger’s

version of the scholastic conception of ordained divine potency.

While the tradition going back to Duns Scotus emphasized the central

importance of the divine will in constituting the ordained power of

God,7 Scaliger rejects the view that any law chosen by God could be

regarded as an expression of divine goodness; rather, he maintains

that only the actual world is the best possible world. Understanding

2

the ordained power of God in this way, however, obviously leads to a

pressing problem concerning species mutability: How could the world

be the best possible world and yet presently lack some biological

species that can develop later? If the world is now as good as it

can get, would not new biological species make it less perfect? Or,

if they would make the world more perfect than it is now, would this

not imply that the world is now less perfect than it could have

been? And if the occurrence of new species would imply that the

world is less perfect than it could have been, how could their

occurrence be understood as an expression of the ordained power of

God?

As it turns out, Scaliger’s writings on natural philosophy con-

tain scattered but interrelated remarks that will lead to a

resolution of this apparent tension. I will proceed in four steps:

First, I will establish that Scaliger makes a substantial claim with

respect to the possibility of the occurrence of plant species that

never existed before. Second, I will spell out the aspects of

Scaliger’s philosophical theology with which his denial of species

fixism seems to be in tension. Third, I will draw an analogy between

Scaliger’s views concerning species changes involving only

previously known species and species changes leading to new species,

an analogy that indicates in which sense species change, for

Scaliger, does not involve the occurrence of new essences. And

forth, I will expand the same analogy in order to give a hint at how

3

the development of new species can be understood as an expression of

ordained divine potency even if it leads to species that are less

perfect than some of the existing species.

2. Scaliger’s Claim

It will be useful first to get a clear grip on the claim that

Scaliger makes with respect to the possibility of the occurrence of

new plant species. Traditionally, the doctrine of species fixism was

understood as a straightforward consequence of two assumptions: (1)

the assumption that a certain species of living beings is defined by

a certain essence common to all individuals belonging to this

species, and (2) the assumption that essences are immutable.8 Species

fixism, in Aristotelian natural philosophy, of course was seen as

compatible with natural changes that involved the transition of one

individual from membership in one species to membership in another

species, as in the transformation of elements (for example, from

fire to air) or in the transformation of mixtures (for example, from

wine to water). It was also seen as being compatible with the

assumption of the existence of “spontaneous generation”, for

example, the generation of bees from the cadaver of an ox. Such

changes involve changes in substantial form (the substantial form of

air is not the substantial form of fire, the substantial form of a

4

mixture of a lot of water with a little wine is not the substantial

form of a mixture of a lot of wine with a little water, and so on);

nevertheless, species fixism holds in such cases because after the

change we encounter substantial forms that belong to previously

existing species.

Scaliger holds that there are two senses in which one can speak

of the possibility of the occurrence of new species. The first sense

does not imply an outright denial of species fixism. According to

the first sense in which new species can occur, “things that already

exist are mixed: such that they will not be inwardly and simply new;

for they are made out of those that already exist, as it were, as

out of parts: which we see happen in graftings which did not exist

before.”9 What is the relevant sense of “mixture” here?10

Unfortunately, Scaliger never discusses what is going on in grafting

in much detail. However, there is a related case, which he also

conceptualizes in terms of “mixture”, namely, the cross-breeding of

animals. His account of cross-breeding is firmly placed in the

context of his conception of a plurality of substantial forms in

each living being. In this respect, he takes up a long tradition

from medieval philosophy that is sometimes called “Latin pluralism”.

According to the basic insight shared by the members of this

tradition, in each living being there is a single dominant

substantial form and a large number of subordinate substantial forms

that actualize subordinate body parts.11 In the following passage,

5

Scaliger explicates in a single breath the nature of the

subordination relation and how this relation can be used to account

for cases of cross-breeding:

[T]he less noble bodies are made for the sake of the more noble

bodies. In the same way, also forms are made for the sake of

forms. For example, it is certain that the forms of a horse and

1 On the textual tradition of De plantis in the Renaissance, see Labowsky,

“Aristoteles De Plantis and Bessarion.” Five Latin translations of the text

are collected in Nicholaus Damascenus, De plantis.

2 See Emerton, The Scientific Reinterpretation of Form, pp. 90–102; Lüthy, “An

Aristotelian Watchdog as Avant-Garde Physicist.”

3 See EE, fol. 319v, and CA, p. 16, discussed below in section 1.2.

4 See EE, fol. 320v, discussed below in section 1.3.

5 See DP, fol. 177r–v.

6 See Ibid., fol. 339v–340r.

7 On the influence of this line of thought in the sixteenth and seventeenth

centuries, see Oakley, “The Absolute and Ordained Power of God in

Sixteenth- and Seventeenth-Century Theology.”

8 See Hull, “The Effect of Essentialism on Taxonomy”; Atran, “Origin of the

Species and Genus Concepts”; Atran, Cognitive Foundations of Natural History, pp.

138–142.

9 EE, fol. 319v: “Species ergo novas gigni posse, duobus modis intelligere

licet. Aut quod ea, quae iam sunt, misceantur: quae sic haud penitus, &

s novae erunt; fiunt enim ex iis, quae sunt, tanquam ex partibus: id

quod evenire videmus in insitionibus, quo non extabant modo.”

6

an ass mix. Since this is so, all arguments [to the contrary]

dissolve. Hence, not only the forms of elements, but also of

wine, and of some animals can be mixed in such a way that out of

two or more there arises an actual per se unity.12

This passage indicates that the subordination relation is to be

understood as a relation of final causation. Some material objects

and some forms are less “noble” than others because they are made

for the sake of other material objects and other forms. With respect

to the structure of living beings the picture that is suggested by

this passage would be the view that bodily organs such as a nose or

an eye, as well as their respective forms, are less “noble” than the

entire body of the living being and its soul because they are made

for the sake of the entire body of the living being and its soul. In

10 For Scaliger’s views on mixture on the level of natural minima, see

Blank, “Julius Caesar Scaliger on Corpuscles and the Vacuum”.

11 On medival theories of a plurality of forms in composite bodies, see

Michael, “Averroes and the Plurality of Forms.”

12 EE, fol. 144v: “… Formarum … illarum naturam esse dixerimus: ut &

misceri, & seiungi queant. Idque propter imperfectionem. Etenim haec

ignobiliora propter nobiliora corpora facta sunt. Sic & formas propter

formas. Quemadmodum equi, & asini formas misceri certum est. Quod si ita

sit, solvuntur argumenta omnia. Ut non solum elementorum formae, sed &

vini, & quorundam animalium ita commisceri possint: ut ex duabus, aut

pluribus unum fiat actu, & per se.”

7

this sense, subordinate forms that are all teleologically directed

towards the dominant forms can be said to be “mixed” and to form a

unity. Such an interpretation is fully consistent with Scaliger’s

claim that the forms of the most perfect living beings do not “mix”

because they are the only ones that are not directed towards any

further goal.13

Scaliger does not tell us whether in the case of the generation

of a mule a substantial form originating from a horse or a

substantial form originating from an ass takes over the role of

dominant form. But whatever the dominant form may turn out to be, it

seems to proceed from an animal with a dominant form of the same

species. And in this sense, a mule should rather be regarded either

as a horse or as an ass with a modified teleological structure of

subordinate forms rather than as an animal that belongs to a species

that did not exist before. Scaliger’s account of cross-breeding may

also give a hint as to how he wants the relevant kind of “mixture”

in the case of grafting to be understood: most plausibly, in

grafting the dominant form of one plant becomes subordinate to the

dominant form of another plant (even if it might be undecided which

form performs which role). If this is what Scaliger has in mind, it

also becomes clear why he thinks that the result does not genuinely

belong to a species that did not exist before: the dominant form in

13 EE, fol. 145r.

8

any case is the dominant form of a plant that existed before

grafting took place.

The second sense in which, in Scaliger’s view, the possibility of

new species can be understood is meant to go beyond the newness that

can be achieved by grafting. According to this second sense, new

species “are in the potency of an agent … For a rose can be produced

which did not exist before. But there is always something there,

because it is in the potency of the rose bush.”14 Unlike the plants

arising from grafting, such a plant belongs to a species that is

“simply” and “inwardly” new; but nevertheless such plants are char-

acterized as the result of something that is “already there” in the

potency of an existing plant. The example given by Scaliger is cer-

tainly bewildering because, from a contemporary perspective, a new

variety of rose would not be a plausible candidate for a new

species. Nevertheless, even if the example is chosen

inconsiderately, what Scaliger has in mind is the question of

species membership. This can be gathered from the context in which

the rosebush passage occurs—a longer discussion of the question

“Whether nature knows animals themselves only with respect to their

genus, or also their parts, or also individuals”, considered by

Cardano and Scaliger alike.15 Cardano gives the following answer:

This is an issue full of doubts: Why are there not more genera of

animals, if nature strives to produce everything that it was able

9

to produce; or why nature has contented itself with these genera

alone … [O]ne or the other horn of this alternative seems

necessary to me: either that the forms of individuals are

constituted by the number and forms of stars; or that they are

perpetually varied through the passage of time, which is indi-

cated by their diversity in different regions … and in different

times.16

Scaliger’s response comes in two parts. The first part complains

about the evasive nature of the first horn of Cardano’s alternative:

“[A]s the number of stars is determinate, nature also has a determi-

nate number, namely, one. Hence, in the same way that we ask whether

14 EE, fol. 319v: “Aut quae sunt in agentis potestate … Rosa enim fieri

potest, ut aliquando non extet. Est tamen aliquid semper, quia est in

Rosarii potestate.”

15 Cardano, De subtilitate, fol. 208r–v; EE, fol. 319r: “Utrum animalia ipsa,

solo genere, Naturae cognita sint; an partes etiam; an ipsa etiam

singularia”

16 Cardano, De subtilitate, fol. 208v–209r: “Dubitatio … maxima est, cur non

plura genera animalium his sunt, si natura quicquid efficere poterat

implere conata est, aut cur his plane solis fuit contentata … [D]uorum

alterum mihi necessarium videtur, vel quod formae viventium numero

quorundam, & viribus Siderum constituantur, vel quod perpetuo varientur

temporum successu: indicio est diversitas illorum in regionibus aliis,

atque aliis, … necnon in temporibus.”

10

nature that is one can produce more than it did, we can also ask:

Can ten stars, say, produce two species in addition to the ten

species that they already produced?”17 The second part of Scaliger’s

response takes issue with the second horn of Cardano’s alternative:

“The other response does not demonstrate a variation of substance

but only of accidents. For if a substance that was one became an-

other through place, place would be the giver of forms. Even humans

would become different, and probably something other than humans, if

placed elsewhere. And the same has to be said to you with respect to

time.”18 Thus, for Scaliger the notion of species membership—for

instance, what distinguishes humans from beings of another kind—is

closely connected with the notion of substantial form. And

Scaliger’s point seems to be that a “variation of substance” amounts

to the occurrence of a new species.

17 EE, fol. 319r: “[U]t certus sit illorum Siderum numerus, certus est

Naturae quoque numerus. Una enim. Quemadmodum ergo quaerimus, an Natura,

quae una est, plures, quam quod fecit, facere queat: sic & illud possumus,

Decem, verbi gratia, Sidera, decem species quae fecerunt: an duas praeterea

facere valeant.”

18 Ibid.: “Altera responsio non demonstrat substantiae, sed accidentium

variationem. Si enim substantia, quae una erat, alia fieret, per locum:

locus esset formarum dator. Ipsi quoque homines alii, & fortasse aliud

essent ab homine, alio translati. Idem quoque de tempore tibi dicendum

est.”

11

Such a reading is confirmed by a remarkable passage from his

commentary on Theophrastus’s De causis plantarum. There, he mentions

that Plinius reports that a (not clearly identified) plant called

“silphium” was newly generated through some extraordinary

meteorological phenomenon.19 Scaliger uses the passage from Plinius

to conceptualize the possibility of the occurrence of new species in

terms of the occurrence of a new substantial form. As he puts it,

the question “[w]hether new species, which never before existed, can

be generated?” boils down to the question “[c]an a new form arise

that shapes matter for its own purposes?”20 As he believes, if what

is reported is true (and he does not adduce any contrary reasons)

“we are forced to confess that a new form can arise.”21 Thus,

Scaliger seems to be committed to the view that, in singular cases,

plants can occur that belong to a plant species that did not exist

before.

Still, one might wonder why the occurrence of a single individual

with a new form should be enough to constitute a new species. Would

not the occurrence of several individuals with certain morphological

similarities matter as well? The answer seems to lie in the close

connection that Scaliger establishes between the notions of form,

19 CA, p. 16.

20 Ibid. “An nova forma fieri potest quae materiae sese aptet?”

21 Ibid.: “Iam si quae de Silphio narrat vera sunt, novam exoriri posse

cogimur fateri.” On silphium, see Plinius, Historia naturalis, 19.15.

12

essence, and species. About a substantial form that shapes matter

for its own purpose he writes that “this is essence and what we call

species.”22 Moreover, he explains that essence is what determines the

activities characteristic of individuals belonging to a certain

species: “A fly cannot exist unless by means of a fly essence. And

the essence determines and constitutes that it nourishes by

sucking.”23 Scaliger points out that such a notion of species derives

from Themistius’s commentary on De anima.24 In fact, Themistius

understands the notion of species not as a logical notion derived

from some similarity between individuals; rather, in his view “a

species loves to be some nature and form. For once human reason is

conjoined with matter, a human being arises.”25 The species to which

an individual belongs thus is understood as a constitutive principle

that this individual can share with other individuals. Such a

characterization fits neatly with Scaliger’s view of essences. For

Scaliger, one could say, essences are principles that determine the

goals of those activities without which individuals could not be

22 CA, p. 16: “Hoc enim essentia est, & quam speciem appellamus.”

23 EE, fol. 323v–324r: “Muscam, nisi per Muscae essentiam esse non posse.

Essentia vero hoc proprium in ea ponit, atque constituit, ut alatur suctu.”

24 EE, fol. 324r.

25 Themistius, Libri paraphraseos In Posteriora Aristotelis, In Physica, In libros De anima, fol.

68v: “[S]pecies natura quaedam esse amat & forma. Nam ratio hominis simul

atque iugata materiae est; homo fit.”

13

what they are. And by determining such goals of characteristic

activities they define species membership.

This is why, for Scaliger, the number of individuals belonging to

a particular species is of no concern. A single rose that instanti-

ates an essence other than the essences of all previously existing

plants would make up a species of its own. But this is what one

would expect in the framework of an essentialist conception of spe-

cies. In fact, in Aristotelian and Arabic cosmologies, heavenly

spheres and heavenly bodies for a long time were regarded as in-

stances of such one-individual species.26 What is new about Scali-

ger’s view is that he applies the concept of a one-individual

species to a different realm—the realm of plants—and that he claims

that a one-individual species that did not exist before can come

into being. Of course, Scaliger never claims that new plant species

necessarily comprise only one member. On the contrary, he easily could

accommodate the view that the process in which an individual rose

belonging to a new species occurs can be repeated in other in-

stances, thereby leading to a species comprising several

individuals. In fact, in the passage referred to by Scaliger,26 Generally, the notion of a one-individual species was not seen as a self-

contradictory in Aristotelian natural philosophy. For the theory of one-

individual species in Aristotelian and Arabic cosmologies, see Wolfson,

“The Plurality of Immovable Movers in Aristotle and Averroes”, pp. 240–243;

Marmura, “Some Aspects of Avicenna’s Theory of God’s Knowledge of

Particulars”, pp. 306–308.

14

Plinius clearly states that silphium occurred in quantities sufficient

to develop a medical use of the plant. Still, with respect to

Plinius’s report Scaliger frames his claim in terms of the

occurrence of a new substantial form (in the singular). In

Scaliger’s view, it is essence, not the number of individuals that

matters for the individuation of a species.

Scaliger’s claim thus seems to be that, in some cases, plants can

arise that belong to no previously existing plant species because

their substantial form instantiates an essence that was not

instantiated by the substantial form of any previously existing

plant. To be sure, there are only two passages in which Scaliger

makes this claim, and in neither passage does he elaborate on the

claim. Nevertheless, it is a claim that deserves attention for two

reasons. First, within an essentialist conception of species it

denies an assumption widely held to be consequence of essentialism

about species, namely the assumption that the number of existing

species cannot become greater. And in this respect Scaliger seems

indeed to have been exceptional among his contemporaries. Second,

the idea that there is something “in the potency” of a rose bush

stands in a close thematic connection with Scaliger’s scattered but

interrelated remarks on the nature of dominant and subordinate forms

in living beings. Taking this background into consideration, as I

will do in section 1.4., will make it clear that Scaliger’s remarks

15

about the possibility of the occurrence of new plans species are

much less ad-hoc than might be evident on first sight.

3. A Problem with Ordained Divine Power

Even if Scaliger’s claim concerning the occurrence of new species,

for reasons just mentioned, deserves attention, it seems at the same

time to be incompatible with Scaliger’s own philosophical theology.

This is the central problem that the present chapter addresses. To

see the problem more clearly, it will be useful to scrutinize

Scaliger’s remarks on divine potency in some detail. Scaliger

accepts the scholastic distinction between absolute divine potency

and ordained divine potency. With respect to the former, he holds

that extraordinary divine interventions are possible: “A single

being is the first, hence all other beings depend [on it] ... But

every dependent being can be changed by the being on which it

depends, if this is a voluntary principle ...”27 Existential

dependence of natural beings on a first being endowed with will thus

implies the possibility of being changed at any time by the will of

27 EE, fol. 405r: “Unum est primum: alia dependent igitur ... At omne

dependens ab eo, a quo dependet, si est voluntarium principium, mutari

potest.” For some other aspects of Scaliger’s philosophical theology, see

Sakamoto, “Creation, the Trinity, and prisca theologia in Julius Caesar

Scaliger.”

16

the first being. Yet, Scaliger does not resort to the absolute power

of God in explaining the possibility of new biological species.

Rather, he regards changes in species membership as an expression of

the order of nature and, hence, of the ordained power of God.28 For

Scaliger, what unites the two kinds of divine power is that divine

power involves both an aspect of immutability and an aspect of

change:

We cannot define providence, but perhaps we may explain it thus:

It is the power of God that is always present to itself and prior

to everything else. Therefore it is simple and one; and for this

reason it is immutable. For if it is prior to everything else, it

is not changed by it, but changes it. If it is present to itself

and simple, it is not changed by itself from within.29

Thus, the immutability of divine power is due to the simplicity of

the divine essence. At the same time, the immutability of divine

power is described as being compatible with changes in the world.

What is more, a certain aspect of divine power accounts for changes28 See DP, fol. 177r–v.

29 EE, fol. 410r: “Providentiam definire non possumus: declaremus sic pote.

Vis Dei praesens sibi semper, & caetera omnia antecedens. Quare simplex

est, & una: atque iccirco immutabilis. Quia si antecedit semper alia, non

mutatur ab illis, sed mutat. Si est sibiipsi praesens, & simplex, non

mutatur intus a seipsa.”

17

that take place according to the order of nature: “Nature is the

power of God with respect to all orderly motions.”30 This can be

understood as Scaliger’s explication of the notion of ordained

divine power. But what does, in his view, this power consist in?

There are some passages that might lead Scaliger’s readers into

believing that he defends some version of pantheism. One of them

runs as follows: “That nature is nothing but God himself … is

evident from the fact that all things that do something act by dint

of the power of the first agent.”31 And shortly afterwards, Scaliger

writes:

That God and nature are the same is evident from De caelo I, 32,

where Aristotle says that ‘God and nature do nothing in vain’ …

In fact, he appointed nature here not as assisting cause, but in

order to explain within the infinite potency, which is known

under the name of God, the potency that he claimed to be ordained

and that we call nature.32

Here, Scaliger invokes the scholastic notion of the ordained power

of God that was traditionally distinguished from the notion of the

30 Ibid.: “Est … natura, potestas Dei ad motus omnes ordinarios.”

31 EE, fol. 120v–121r: “Nihil esse aliud Naturam, quam Deum ipsum … ex eo

patet, quod omnia quaecunque agunt aliquid, in vi ac virtute primi agentis

agunt.”

18

absolute power of God. Later, he mentions that Duns Scotus explains

the distinction between “absolute” and “ordained” power in juridical

terms: A person acts “ordinarily” who acts according to a law. But

two cases can be distinguished. Either the person is not able to

change the law. In this case, there would be no other way for her to

act rightly—every act that contradicts the law would be inordinate.

Or the person is able to change the law. The ability of changing the

law is “absolute” potency. Scaliger notes that when we follow the

lead of Scotus and apply this conception to God, we come to the

conclusion that, due to his “absolute” potency, God could change the

law such that he, after the change is completed, is able to act

rightly according to the new law, again in an “ordained” way.33

At this juncture Scaliger departs from Scotus. He notes that, ac-

cording to Scotus, another “law also would be the right law, if it

were decreed by God.” And he concedes that “it is evident: if God

makes another law, this law will be the right law in the future.”

However, he objects:

32 EE, fol. 121r: “Idem esse Deum & Naturam patet ex primo De caelo: Deus,

inquit, & Natura nihil frustra facit … Naturam vero hic apposuit non quasi

adiutricem, sed ut explicaret in potentia infinita, quae in Dei nomine

cognoscitur, potentiam, quam voluit ille esse ordinariam: quam Naturam

appellamus.” See Aristotle, De caelo I, 4 (271a33). On this principle, see

Lennox, “Nature Does Nothing in Vain.”

19

[I]n every action there is only one right action: and this is

constituted by The Right, that is, what is right in the highest

degree, that is, by God himself. Therefore, whatever is right

besides this does not belong to God, but to something that is not

God. Because to do something less good implies a privation of

supreme goodness and supreme power … Hence, he could act differ-

ently, because in the highest potency a minor potency is com-

prised, as well. Thus, he could do so out of the immensity of

potency. But out of the highest goodness, which is the rule for

potency … he does not want to be capable of less than to be ca-

pable of acting well.34

Thus, Scaliger’s conception of the “ordained” power of God is

closely connected with his view that God acts in the best possible

way. God could have chosen, by means of his “absolute” power, a

different world. Nevertheless, the world that he actually has chosen

is the best possible world.35

33 EE, fol. 320r–v. See Duns Scotus, Ordinatio, I d. 44. On Scotus’

distinction between absolute and ordained power, see Pannenberg, Die

Prädestinationslehre des Duns Scotus, pp. 68–72; Pernoud, “The Theory of the

Potentia Dei According to Aquinas, Scotus, and Ockham”, pp. 84–86;

Courtenay, “The Dialectic of Divine Omnipotence”, pp. 12–13; Oakley,

Omnipotence, Covenant, and Order, pp. 55–56; Funkenstein, Theology and the Scientific

Imagination, pp. 132–133.

20

This is a substantial difference between Scotus’ and Scaliger’s

views on the goodness of the laws underlying the natural world: For

Scotus any consistent combination of laws chosen by God would, by

this very fact, be good and an expression of the divinely chosen or-

der; for Scaliger only one single combination of laws can be the

best possible one and, for this reason, is chosen by God. In this

sense, there is only a single combination of laws that can be

regarded as the expression of the ordained power of God. Other

possible combination of laws would be inordinate because they would

realize a world that is less good than the actual world. For Scotus,

God could act ordinately in all logically possible ways; for

Scaliger, God could act ordinately only in a single possible way

that corresponds to divine goodness.

34 EE, fol. 320v: “[I]n unaquaque actio unum tantum rectum est: idque a

Recto, id est a summo recto, Deo ipso constitutum. Quare quodcunque praeter

illud rectum est, non est Dei, sed non Dei. Propterea quod minus bene

facere capessit privationem summi boni, & summae potestatis ... Potest

igitur aliter facere: quia summa in potestate minor quoque comprehenditur

potestas. Ex immensitate igitur potentiae potest. At ex summa bonitate,

quae est potentiae regula, neque a potentia essentia diversa ... non vult

minus posse, quam bene posse.”

35 Ibid.: “Potuit quidem, potest, poterit creare Mundos alios; sed non fuit

optimum. At summum bonum semper, quod optimum est, vult: quod per

Sapientiam cognoscit.”

21

This difference is connected with a no less substantial differ-

ence in the importance that Scotus and Scaliger assign to the divine

intellect. For Scotus, what matters is that the divine will chooses

one consistent combination of laws; the divine intellect is involved

in this process, but for Scotus the intellect’s role reduces to

providing the will with information concerning the coherently

thinkable combinations of laws. In this sense, it is not the divine

intellect that is a source of the goodness of the chosen combination

of laws; rather, the chosen combination of laws is good because it

is chosen by the divine will. And because the divine will is free to

choose any logically coherent combination of laws, any logically

coherent combination of laws chosen by the divine will would be the

expression of divine goodness. By contrast, Scaliger describes the

role of the divine intellect as follows: “God generates ... out of

himself, in himself, the understanding of himself, in the same way

always the same and equal to himself. Because he does not understand

by means of species but through the presence to himself.”36 For

Scaliger, what comes first is the insight of the divine intellect

into the divine nature, an insight, which includes an insight into

the divine goodness and omnipotence. This gives an answer to why,

for Scaliger, the divine will chooses the combination of laws that

22

the divine intellect regards as the best: the divine intellect

determines the divine will to create the best of all possible

combinations of laws because the divine intellect possesses

reflective knowledge about divine goodness and omnipotence. In this

sense, for Scaliger’s view of how the divine intellect is

constitutive for the ordained power of God is very different from

Scotus’.

Interpreting the ordained power of God in the way Scaliger does

makes the question of how new biological species can come into being

even more pressing than from the perspective of Scotus’ in-

terpretation. For Scotus, the actual world is the best in the sense

that adding or subtracting beings in it would make it less good. In

this sense, every possible world is a sort of optimum that would

become less good by adding or subtracting beings. Scotus’ position

seems to imply that there could other biological species than those

that actually exist; but they would have to be part of other

possible worlds. For Scotus, relatively to laws that flow from other

possible acts of the ordained power of God, they could be part of

other natural orders; but given that laws that flow from the actual

act of the ordained power of God, their occurrence would be

inordinate—their occurrence would be possible but it would make the

36 EE, fol. 473r: “Generat ... ex seipso, in seipso, suiipsius

intellectionem Deus, eodem modo eandem, & aequalem sibi. Quia non

intelligit per speciem, sed per suiipsius praesentiam.”

23

world less good. By contrast, if there is only one possible course

of action that the ordained power of God could have taken, thinking

of other biological species as part of other natural orders does not

help. This is why for Scaliger other possible worlds cannot be

understood as alternative outcomes of the ordained power of God. And

in fact, Scaliger does not invoke alternative natural orders when he

speaks about the possibility of the occurrence of new species of

living beings. Rather, he regards this possibility as being inherent

in the actual world.

On first sight, such a view seems to face insurmountable obsta-

cles within Scaliger’s own conception of divine agency. Consider the

following implication of the notion of perfection: “Perfect is that

to which nothing can be added. Hence, an entity to which nothing can

be added will exist perpetually. Likewise, an entity in which

nothing belonging to essence can be changed.”37 Hence, the perfection

of the world implies that nothing pertaining to the essence of the

world could be changed without making the world thereby less

perfect. Creating anything in addition to what the world already

therefore would be incompatible with the perfection of the world:

“Can God create and add there something new? He can. But he does not

want to be able to: because he would accuse himself of a less

24

perfect work than what he had put in his previous work.”38 Conse-

quently, it seems as if Scaliger would have to regard the occurrence

of new species of living beings as a possibility that would go

beyond the ordained power of God.

4. Species Change as Relational Change

Does Scaliger’s philosophy contain the resources to resolve the ten-

sion between his denial of species fixism and his conception of the

ordained divine power? I believe that it does. To see this, we will

first need to get some grip on his views on changes in species mem-

bership involving only previously existing species. Such cases obvi-

ously do not pose any problems for Scaliger’s theological views;

nevertheless, they provide a helpful background for understanding

his solution for those cases that seem to be in tension with his

views on the ordained power of God. Scaliger’s scattered remarks

give some coherent hints at how his ontology of a plurality of

substantial forms in living beings allows for such changes in

37 EE, fol. 319v: “Perfectum est, cui nihil addi potest. Perpetuo igitur

illud erit, cui ne adimi quidem quicquam. Denique in quo nihil essentiae

mutari queat.”

38 EE, fol. 320v: “An Deus ibi novi quicquam possit & creare, & addere?

Possit. Sed nolit posse: quia suiipsum argueret imperfectioris operae, quam

in priore opere posuisset.”

25

species membership involving only previously existing species.

Moreover, they suggest that the processes underlying the occurrence

of new species of living beings are closely analogous to the

processes underlying the changes in species membership involving

only previously existing species.

Scaliger mentions two examples for transformations between

previously existing species that were widely discussed in ancient

biological works: the change of darnel into wheat, and the change of

water-mint into mint. Of course, from a contemporary perspective, we

would interpret such cases as changes from a wild variety to a

cultivar. Nevertheless, what Scaliger has in mind in discussing

these cases, whether empirically adequate or not, is the issue of a

change in species membership. This becomes clear when, with a view

to these cases, he is careful to note that change can take place

either with respect to substance, or quantity, or quality.39 He

maintains that while changes with respect to quantity and quality do

not constitute differences in species, a change in substance does.40

And such a change of the whole species (mutatio totius speciei), in his

view, takes place when water-mint changes into mint.41 He describes

this change as follows: “When mint changes into water-mint, or vice

versa, this happens due to the affinity of forms; and if the species

26

differs also matter differs.”42 Clearly, changes in species member-

ship here are connected to changes on the level of substantial

forms. However, what does Scaliger have in mind when he speaks of

the “affinity of form”? Commenting on Theophrastus, he analyses the

analogous case of darnel and wheat as follows:

At the same time, he shows the mode in which darnel arises and

explains the reason by means of which this can take place. The

mode is the following: if the seed is inwardly corrupted, the

form of the plant is not abolished but becomes another form. He

proves that this can take place when he says that the nature of

plants is full of life, and indeed fuller of life than the nature

of animals and therefore productive.43

39 CA, p. 288.

40 Ibid.

41 Ibid.

42 EE, fol. 386v: “[U]bi transit in Sisymbrium Menta, aut e contrario,

propter formarum affinitatem: si species aliud est: materia quoque aliud.”

43 CA, p. 230: “Simul ostendit modum quo nascatur Lolium: simul explicat

rationem, qua id fieri possit. Modus est, non corrupto penitus semine

aboletur plantae forma, sed fit alia. Quod vero fieri possit, demonstrat,

quum dicit plantarum naturam vivacem esse, ac sane vivaciorem quam naturam

animalium atque iccirco proficere.”

27

Darnel is a case in which a plant of one species has its origin in

the corrupted seed of a plant of a different species. The corrupted

seed no longer carries the form of the plant from which it

originated. But it is also not altogether different from the form of

the plant from which it originated. As I have argued elsewhere, it

seems most plausible to understand this passage and those about mint

and water-mint in the context of Scaliger’s conception of a

plurality of substantial forms in living beings. If this is what

Scaliger has in mind, what underlies his account of species

mutability is the view that domination relations between substantial

forms can break down such that a previously subordinate form becomes

the substantial form of a new living being.44

Scaliger gives an analogous reading to Theophrastus’ account of

cases of “spontaneous generation”:

[O]ut of a human being there does not arise a slime, out of which

again a human being could arise. From a calf, bees are created,

but the nature of bees never returns back into a calf … Rather,

out of those things that were in the first instance created

together, other things follow on those things that decay at the

same place. For it is manifest that some kinds of wood … have

natural rudiments of another species within themselves. If this

44 See Blank, “Julius Caesar Scaliger on Plant Generation and the Question

of Species Constancy.”

28

nature persists and remains intact, it does not so much re-inte-

grate while being in the slime of decayed things; rather, a new

generation out of old principles takes place.45

Since the “natural rudiments of species” and “old principles” con-

tained in a living being develop into the substantial forms of

livings beings belonging to another species, they can most plausibly

be understood as subordinate forms dominated by the substantial form

of the plant.

Scaliger’s claim that in a rose bush “there is always something

there” that accounts for the generation of a plant belonging to a

new species46 can well be understood against the background of these

remarks. Most plausibly, as in other cases of changes of species

membership, what is “always there” in the rose bush are some “old

principles” or subordinate forms that subsequently become dominant.

If this is what Scaliger has in mind, then what is analogous between

cases of changes in species membership involving only previously

45 DP, fol. 178r: “Ex vitulo concreantur apes: nunquam retro redit in

vitulum apiculae natura … Sed quibus primordiis illis in locis

concreabantur olim iis, qui fuerunt ibi contriti, subnasci alios. Ligna

enim quaedam … habere illiusce speciei secum rudimenta naturalia,

manifestum est. Qua natura superstite, atque incolumi permanente, non tam

redintegratur in contritorum tabo, quam nova ex veteribus principiis

substituatur generatio.”

46 EE, fol. 319v.

29

existing species and the occurrence of a new plant species is that

in both cases changes in relations of domination and subordination

between substantial forms in living beings take place. Can such a

process lead to plants that belong to previously non-existing

species? Consider that, according to Scaliger, all substantial forms

have been created at once in the act of creation.47 This seems to

imply that, since then, some forms—for example, the forms of parts

of organic bodies—have always functioned as subordinate forms. These

forms functioned as life-principles of parts of living beings (or

other composite substances), but never as life-principles of living

beings themselves. Accordingly, the essences instantiated by them

functioned as essences of parts of living beings (or other composite

substances), but not as essence of living beings themselves.

Likewise, these essences defined species of parts of living beings (or

other composite substances), but not species of living beings

themselves. During all this time, there was no living being that

belonged to the species individuated by such an essence. However,

assume that once the domination relation between the dominant

substantial form and such a subordinate substantial form breaks

down, and that during this process a subordinate form becomes the

active principles of a living being. In such a case, we are in the

47 With one notable exception: With respect to the origin of human souls,

Scaliger accepts the theological doctrine of separate acts of divine

creation (EE, fol. 16v).

30

presence of a living being whose essence is determined by a

subordinate form turned dominant. This essence never before

functioned as the essence of any other living being or,

equivalently, there never before was a living being that shared the

same essence. In such a case, while the substantial form dominating

in this living being is old—indeed, as old as the universe—the

living being belongs to a species that is new.

In this way, the possibility of the occurrence of new species

does not violate the condition that, in the best possible world, no

new essences can come into being. This, I believe, is an important

part of a solution of the problem of how the view that new species

can occur is compatible with Scaliger’s conception of the ordained

divine potency. Still, it is an incomplete solution. Recall that

Scaliger believes that substantial forms that are capable of

occurring as subordinate forms are less perfect than dominant

substantial forms. So, why should not the death of a more perfect

living being and the emergence of a living being dominated by a

previously subordinate and, hence, less perfect, form be understood

as diminishing the perfection of the universe? In fact, there is an

analogous problem for the degeneration of mint into water-mint or of

wheat into darnel. And this is why the analogy between species

change involving only previously existing species and species change

involving also previously non-existing species is helpful also in

this case.

31

5. Species Change and Ordained Divine Power

Let me begin by considering whether Scaliger’s claim that nature is

the ordained power of God implies that God is an active power im-

manent in things. This is one of the relevant passages:

[I]f a human being deliberates about actions, it has also this

from nature …: By its own nature, it is capable of deciding about

two contradictory options such that it chooses one of them. From

this, we also understand that divine providence is immanent in

all things, but not in the same way. For it permits some; others

it makes inclined by itself, that is, by means of an influence;

others by means of immaterial agents; others by means of material

agents, from which the disciplines arise out of the teaching of

sciences; others by means of principles that are innate with us

…48

48 EE, fol. 410v–411r: “[S]i homo consulit de rebus agendis, hocque habet a

Natura …: Natura sua erit homo aptus natus ad disceptandum de duobus

contradictoriis; ut alterum eligat. Hinc etiam intelligemus: providentiam

divinam rebus omnibus imminere: at non eodem modo. Permittit enim quaedam:

alia insinuat per se, id est afflatu: alia per ministros immateriales: alia

per materiales, unde oriuntur disciplinae, ex scientiarum communicatione:

alia per principia naturalia connata nobis …”

32

Scaliger indeed seems to be committed to the claim that, in some

sense, divine providence is immanent. But it is not evident with re-

spect to all cases mentioned why he believes that divine providence

is immanent. It seems rather enigmatic why he believes that divine

providence is immanent in the cases in which God does not interfere

with the course of events. Other cases involve immanent divine

providence in a quite obvious way, namely cases of direct divine

intervention and intervention by means of intermediary beings. These

cases would fall most plausibly under the heading of “special

providence”—something that does not happen according to the ordained

course of things. But how should one understand Scaliger with

respect to the most interesting class of cases: the agency of

natural (material or immaterial) agents?

The relation between God and natural beings is one of the points

in which Scaliger markedly departs from Scotus. He attributes to

Scotus the following line of reasoning: “Things have essence and

existence. Therefore, in creation the things that had essence in the

divine mind, that is, in the ideas, undergo change through the

addition of existence.”49 Scaliger comments:

49 EE, fol. 17r: “Res habere essentiam, & existentiam. Igitur in creatione

res, quae habebant essentiam in mente Divina: id est in ideis: mutationem

passas, addita existentia.”

33

This is false. For God would create nothing but an accident,

namely, existence itself, which is an accident of essence. That

is, he would add nothing to essence that would make something

other than essence or more than essence. But this is contrary to

the definition of creation. For this was the constitution of sub-

stance out of nothing. If existence were a substance that differs

from essence, there already were two substances. If it is an ac-

cident, God would create an accident. If it is the same as es-

sence, God would create nothing ... Therefore one has to say: God

did not add existence to an essence that was in his mind …

Rather, he produced new forms that are similar to these essences,

and that are not simply univocal but analogous: the ones are only

in his will, while he made the other such that they exist in a

new contingent manner.50

50 Ibid.: “Hoc falsum est. Quia Deus nihil creasset, nisi accidens: nempe

ipsam existentiam, quae essentiae accidens est. Nihil sane addit essentiae,

quod eam faciat non essentiam, aut plusquam essentiam. Hoc autem adversatur

definitioni creationis. Erat enim constitutio substantiae ex nihilo. Quod

si existentia est diversa substantia ab essentia: iam essent duae

substantiae. Si accidens: Deus accidens creasset. Si est eadem: nihil

creasset ... Dicendum igitur: non esse a Deo additam existentiam essentiae,

quae erat in mente sua … Sed prompsit formas novas, illis similes, non

univocas simpliciter, sed analogas: quae non erant nisi in eius voluntate:

quas fecit, ut existerent novo modo contingenti.”

34

For Scaliger, the process of creation is not a process in which

existence is added to essences that are previously present in the

divine mind in such a way that the essences of created things would

be identical with the essences in the divine mind. Rather, things

have their own essences by means of which they differ from mere

accidents. In this sense, natural beings are substances in their own

right, and divine immanence cannot be understood as an immanence of

divine essence in created beings.

If created beings are substances in their own right, their

activities cannot be interpreted as an activity of divine essence.

In which way, then, can the activity of created substances be

understood as an expression of divine providence? And how could the

occurrence of an individual belonging to a less perfect species than

the individual from which it originated be understood as being

compatible with, and even an expression of, the divine will to

create the best possible world? Scaliger connects his views

concerning relations between biological species closely with his

views on the relation between God and created world:

The first principle was not able to produce something that is

entire similar nor entirely dissimilar to itself. For it was

unable to produce something similar because, what comes into

being, suffers, and what suffers, suffers from something more

potent. And it was unable to produce something dissimilar,

35

because action and agent do not differ in it. Hence, the act, or

the product, was necessarily similar in some way and dissimilar

in some other way. Therefore, because the principle is one, the

world was one and not one ... Because it is one it is eternal;

for it does not have any counterpart or contrary. Because it is

not one, it is not eternal; for it is constituted by contrary

parts that act on each other destroying each other. Hence, its

eternity consists in succession, its unity in continuation. (I

now understand eternity as perpetuation, to which the principle

imposes an end when it seems fitting to it.) Therefore the world

must have two ideas of forms. One is particular, relating to each

of the species contained in it, relating to the generation,

motion and extension in those entities by means of which it is

not one. The other is universal and serves the purpose of

conserving unity.51

In this passage, Scaliger combines a sense in which the world is one

with a sense in which the world is not one. The world is not one

because it is composed of parts whose causal relations are opposed

to the conservation of the parts. In this sense, there is a

perpetual change in the parts constituting the world. At the same

time, the world as a whole does not stand in causal relations that

could be opposed to its conservation to anything external to it. In

this sense, the perpetual change in the parts constituting the world

36

is not contrary to the view that the world as a whole does not

undergo destruction. Scaliger is also explicit about the distinction

between ideas and forms. It seems plausible to understand ideas as

essences in the divine mind, while forms that exist in the natural

world are the factors that account for the substantiality of created

beings. Interestingly, Scaliger claims that ideas relate in a dual

way to forms: In one way, ideas relate to forms under the

perspective of how species are constituted by natural particulars

that undergo processes such a generation and motion. In this way,

ideas relate to forms under the perspective of what makes the world

a being that is not one. In another way, however, ideas relate to

how forms account for the conservation of the unity of the world.

51 EE, fol. 6r: “Non potuisse primum principium quicquam efficere, quod sui

esset, aut simile penitus, aut dissimile. Nam simile non poterat: quia quod

fit, patitur: quod patitur, a potiore patitur. Dissimile non potuit: quia

actio, & agens in ipso non differunt. Igitur actum, sive factum, aliquo

modo simile, alio dissimile fuit necessario. Quamobrem cum ille sit unus:

Mundus fuit unus, & non unus ... Etenim quia unus est, aeternus: non enim

habet comparem, aut contrarium: quia non unus, non aeternus. Ex contrariis

enim ac mutua corruptione inter se grassantibus partibus constitutus est.

Eius igitur aeternitas in successione: unitas in continuatione. Intelligo

nunc aeternitatem, perptuationem: cui finem imponet, cum ei visum fuerit.

Dua igitur ideas formarum habere mundum oportuit. Una est particularis, sua

cuiusque speciei, ad generationem, motum, prorogationem in iis, per quae

est non unus. Alia est universalis ad conservationem unitatis.”

37

What does Scaliger have in mind? One of his responses to Cardano

may give a clue. Cardano argues that species of living beings are

not made for the sake of other species, because many individuals

belonging to species “live and die for their own sake” (sibi vivant &

moriantur).52 This is Scaliger’s reply:

When you say that not all flies are eaten by the swallow, [this

is so because] these individuals miss by chance the end of their

species ... [This is the] proof: That without which something

cannot exist in nature is necessary for it or made for the sake

of it. Without the fly the swallow cannot live.53

Here, Scaliger gives a clear voice to the idea of a teleological

relation between biological species. This teleological relation does

not necessarily hold on the level of individuals—of course, not all

flies are eaten by the individuals belonging to species that feed on

flies—but the teleological relation on the level of species shows

itself in the existential dependence of one species on another—the

case in which one species could not survive without feeding on

52 Cardano, De subtilitate, fol. 209r.

53 EE, fol. 323r: “Nam quod ais, non omnes Muscas ab Hirundinibus devorari:

sane illa individua fortuito absunt a fine speciei ... Demonstratio. Sine

quo quicquam existere non potest in Natura: id est illi necessarium, atque

propter illud factum. Sine Musca non potest Hirundo vivere.”

38

members of another species. As it turns out, such relations of

existential dependence are, in Scaliger’s view, often reciprocal:

[T]hose who think that species are made by God for the sake of

variety, not for the sake of a certain end, propose no other end

in nature than being idle ... In order for this fly and this

butterfly to be able to dance on holidays, it is burdened with

serious duties towards the more noble species ... For variety is

not the goal that nature pursues. Rather, it is a means for the

perfection of the universe. For nature itself is in a manifold

way one; [a unity] which consists in how the forms are

constituted, in their mutual necessity and order.54

Here, Scaliger characterizes the relation between different species

in terms of a relation between different substantial forms. In fact,

the mutual dependence between substantial forms for him is only one

case of a whole group of relations of existential dependence in na-

ture:54 EE, fol. 323r–v: “Igitur qui putant, ob varietatem, non ad certum finem

species a Deo comparatas: nullum alium in iis Naturae finem proponunt, quam

ineptire ... Ut illa Musca, & Papilione festis luserit diebus: seria opera

impensa sit nobilioribus speciebus ... Non enim varietas finis est, in quem

intandat Natura: sed via ad perfectionem universi. Est enim hac ipsa

multiplicate unum. Quod constat formarum constitutione, mutua

necessitudine, atque ordine.”

39

Because the creator wants to preserve the world, he joined to the

parts of each genus a propensity and efficient power to fulfil

mutual duties. In this way, wheat serves as the matter for a

mouse, the force of the sun as the form. In this way, form gives

to matter that it is this particular something; matter gives to

form that it is exists here and now ... Form gives to the acci-

dents that they exist; the accidents give to form that it acts in

this way … In this way the forms of species are mostly conserved

through their utilities and the utilities through the forms. Such

that even the human species is assisted by most of the other

species; and the human species assists many of them.55

For Scaliger, relations of mutual existential dependence between

biological species are an instance of a whole group of relations of

existential dependence that lie at the heart of his conception of

the unity of the world. And such relations of mutual existential

55 EE, fol. 324r: “Quia vero vult Opifex illum conservari: mutuorum

officiorum & propensionem, & effectionem cuiuscunque generis partibus

adiunxit. Sic pro materia est triticum Muri, pro forma Solis vis. Sic

materiae forma dat, ut sit hoc aliquid: formae dat materia, ut existat hic,

& nunc ... Accidentibus dat forma, ut sint: formae dant accidentia, ut sic

agant … Sic specierum & formae ab utilitatibus, & a formis utilitates mutuo

maxima ex parte conservantur. Ita ut homo quoque a magna parte iuvetur

specierum: multas iuvet ipse.”

40

dependence between biological species belong to those relations that

the creator brought into being in order to preserve the existence of

the world. In this way, fulfilling functions towards individuals of

other biological species belongs to the activities of substantial

forms determined by the ordained power of God: only if substantial

forms fulfil such functions can they be said to be part of a natural

world ordered in the most perfect way.

Scaliger explicitly connects the issue of species change with the

issue of a lawful order of nature when he claims that species change

takes place “by means of a decree of nature that strives towards a

certain end through certain laws.”56 The concept of law at stake here

is not one that has to do with observable empirical regularities.

Rather, it is the concept of law understood as an expression of the

ordained power of God:

[N]ature is for all things by itself a principle by means of

which they are what they are … If all plants are determined by

nature, they are also determined by necessity in what they are.

Some of them, I say, perpetually, like those that do not undergo

change. Some of them not perpetually, like those that undergo

change, either by means of the seed that brings forth wheat or

after sowing, as we said about mint. Nevertheless, the principle

56 Scaliger, Animadversiones in historias Theophrasti, pp. 110–111.

41

that consists in being mutable is itself immutable. For this

reason, nature is the ordained power of God …57

Both seeds and young plants are determined to develop in a particu-

lar way, but their way of being determined is compatible with the

view that both seeds and young plants can develop into plants of a

species other than the plant from which they originated. For Scali-

ger, the transition of an individual from one known species to an-

other known species is laid down in the natural powers of things

themselves, which are understood as secondary causes created ac-

cording to the decrees of divine providence. In this way, whether

the transition leads from a less perfect being to a more perfect

being or from a more perfect being to a less perfect being is

irrelevant for the question whether such changes in species can be

understood as expressions of the ordained power of God. Even if

they, in a particular case, lead to the existence of a less perfect

being, what matters from the perspective of divine decrees is the

resulting perfection of the universe. And, as we have seen, the

perfection of the universe is constituted by relations of mutual

existential dependence between species. God wants what is best for

the preservation of the universe as a whole, and if, due to the

mutual dependence between species, the occurrence of some

individuals belonging to a less perfect species is required for the

preservation of other species, this is exactly what the laws

42

underlying the best possible world demand. An analogous

consideration can be applied to individuals that belong to new

species: These new species are not necessarily more perfect than

previously existing species, but again, the degree of perfection of

a particular species is not what matters. Rather, if the divine will

to create the best possible world boils down to permitting those

57 DP, fol. 177r–v: “[N]atura est omnibus rebus naturalibus principium per

se, ut hoc ipsum sint, quod sunt … Quod si natura constant omnes plantae,

necessitate quoque constabunt tales. Tales, inquam, perpetuo, velut eae,

quae non mutantur. Tales non perpetuo: sicut illae, quae mutantur, vel

semine quod patitur Triticum: vel post sationem, quamadmodum de Menta

dicebamus. Quippe hoc ipsum principium, quod est esse mutabilem, immutabile

est. Ergo natura vis est ordinaria Dei …”

43

species to develop that are most useful for the preservation of

other species, the occurrence of new species is compatible with the

ordained divine potency as long as they contribute to the

preservation of other species in the best possible way.

6. Conclusion

Thus, the tension between Scaliger’s claim that the occurrence of

new species of plants is a genuine possibility and his view that God

creates the best possible world is only apparent. It can be resolved

by paying attention to two elements in Scaliger’s thought: The first

44

is his view that what matters for species change is a change in the

relation of subordination and domination between substantial forms.

As we have seen, he applies such an analysis to cases of species

change involving previously known species, and it can consistently

be extended to an analysis of cases of species change leading to new

species. New species do not require new essences and are therefore

compatible with the requirement that to the best possible world no

essences can be added. The second element relevant for dissolving

the apparent tension is Scaliger’s view that what matters for the

perfection of the universe is not the sum of the degrees of

perfection of single species but rather the capacity of single

species to contribute to the preservation of other species. Species

changes leading to less perfect species do not diminish the

perfection of the universe as long as the occurrence of less perfect

species is best for the preservation of other species. Again, this

thought can consistently be extended to the occurrence of new

species: as long as they contribute to the perfection of the

universe as a whole, their occurrence can be understood as being

compatible with, and an expression of, the ordained power of God.

45