Wat als je "formele essenties" als "mogelijkheden" leest – zoals Alan Donagan deed 
In aansluiting op discussies die we hier voerden over “essenties van niet bestaande dingen” (en in dat verband de betekenis van ‘essentia formalis’ en ‘existentia actualis’ enzomeer, wil ik graag mogelijk verhelderende teksten brengen uit Donagan’s Spinoza (1988). Ik doe dat in twee blogs.
En passant noteer ik dat ik erg verhelderend vond dat hij erop wijst dat 2/Def2 geen definitie van essentie geeft maar van “wat behoort tot de essentie”: “What he [Spinoza] defines in Part II is not the expression ‘essence’, but the expression ‘belonging to’ (pertinere) as it applies to an essence.” [p. 59]
Ik vond steeds het moeilijke van de zgn. "essentie-definitie" dat je daarmee nog niet te weten komt wát essentie precies is (en ik ben de enige niet). Maar de valkuil is dus dat we het ten onrechte “essentie-definitie” noemen: het is een definitie van “wat tot de essentie behoort” – wat er de noodzakelijke én voldoende voorwaarde voor is.
Voor ik verder ga, wil ik eerst vaststellen dat Morgen Laerke niet fair is (niet charitable, zoals ze in de Angelsaksische wetenschappelijke wereld graag schrijven) met in zijn “Aspects of Spinoza’s Theory of Essence. Formal essence, non-existence, and two types of actuality” [cf. blog] op p. 2 Donagan mee te nemen onder “Some commentators have compared formal essences and non-existing modes with possibilia, thus making of the realm of formal essences in important respects comparable to Leibniz’s regio possibilitatis.” Inderdaad benoemt Donagan, ook in andere teksten die ik al eerder citeerde, de formele essenties van niet bestaande dingen als “mogelijkheden die vervat liggen in de attributen”. Maar op meerdere plaatsen (ik citeerde er al enkele, cf. reactie op blog, maar hij doet dat nog uitvoeriger in dit boek in onderstaande passage), bestrijdt hij de betekenis van possibilia die Leibniz eraan geeft.
Opmerkelijk vond ik al dat Donagan zijn boek niet meteen met de Ethica begint, maar eerst uitvoerig vanuit de TTP laat zien hoe de naturalistische God van Spinoza “eruit ziet”. Dit komt telkens terug, zoals in onderstaand uitvoerige citaat blijkt (referenties laat ik achterwege).
In hoofdstuk 5, “God as Absolutely Infinite Substance”, bespreekt Donagan Spinoza’s godsbewijzen. Bij de behandeling van het tweede bewijs geeft hij kritiek op Leibniz, en formuleert hij een leeswijzer voor hoe je Spinoza als het gaat om possibilia dient te lezen.
The second [proof] runs: the more attributes a thing has, the more reality or being it has (E 1 p9), and 'the more reality belongs to the nature [i.e. the essence] of a thing, the more power it has, of itself, to exist' the conclusion being obvious (G II, 54/5-7). The best commentary on these proofs is a paper, 'De Rerum Originatione Radicali', which Leibniz wrote twenty-one years after meeting Spinoza in 1676. In the following passage from it, he states a principle of plenitude more general than that employed by Spinoza in both forms of his proof.
[F]irst, from the fact that
something exists rather than nothing, we must acknowledge that there is a
certain exigency (exigentia) to
existence in possible things or in possibility itself or essence, or (let me
say) a praetensio towards existing.
Put briefly, essence per se tends to
existence. Whence it follows in turn that all possibilia or [things] expressing essence or possible reality, tend
to existence with a right (jure)
proportional to [their] quantity of essence or reality, or to the grade of
perfection which they involve; for perfection is nothing but quantity of
Hence, as manifestly as can be, it is understood that, out of the infinite combinations of possibilia and possible series, that exists through which the greatest quantity of essence or possibility is brought into existence.'
As Leibniz describes it, combinations of possibilia differing in strength struggle to exist, and the strongest prevails - that is, the combination having the greatest quantity of essence. Although Spinoza was more reticent, his proof, if taken literally, implies what Leibniz makes explicit. Yet is [=it] is repugnant to the naturalism of the Tractatus Theologico-Politicus to think of non-existent possibilities as doing anything at all, much less as struggling against a more powerful enemy.
Benson Mates raises the same questions about Leibniz's generalization of Spinoza's proof ‘[T]alk of possible things,' he observes, 'although it permeates the Leibnizian writings, is, if taken literally, productive of paradox and quite foreign in spirit to his metaphysical outlook.’ Non-existent logically possible beings can make no difference to actual existing ones. Only actual existents can actually cause anything. These truisms were as obvious to Spinoza and Leibniz as they are to philosophers now. And so, as Mates argues,
it would be absurd to take literally Leibniz's oft-repeated principle that all the possibles 'strive for existence' (see PS VII, p. 195). In the context of his philosophy this obviously means that whatever is compossible with what exists, exists—i.e., if God could create x, then he would do so unless the creation of other things prevents it.
A parallel line of thought holds for Spinoza. Essences, i.e. possibilia, do not fight among themselves, the winner being rewarded with actuality. When Spinoza says things that imply that they so fight, they should be construed as figurative if they can be.
Can they be? In a letter to Johannes Hudde, Spinoza described his God in a way that points to a naturalistic sense that might underlie his talk about the striving of possibilia.
[S]ince the nature of God [that is, of an absolutely infinite being] does not consist in a certain kind of being [he wrote], but in Being, which is absolutely unlimited (indeterminatum), his nature also demands (exigit) everything which perfectly expresses τò esse, because otherwise his nature would be limited and deficient (Ep36—G IV, 185/29-32).
This implies, not that a possible absolutely infinite being defeats the other possibilia in a struggle for existence, but that the nature of an actual absolutely infinite being 'demands' that it consist of every attribute expressing an eternal and infinite essence. According to the view of things Spinoza put forward in the Tractatus Theologico-Politicus, passages about what an absolutely infinite being's nature demands should be construed as being about what, according to the laws of nature, it must be. Nor would it be contrary to that general view that it be a law of nature that any essence of a substance that is constituted by an attribute expressing an infinite essence is also constituted by every other such attribute.
If two substances cannot have any attributes in common, and if there are n attributes, then an actual substance whose essence is constituted by n attributes may well be said, for the sake of vividness, to prevent substances with fewer than n attributes from existing. And from that it is a short step to imagining possible substances as engaged in a struggle for existence, in which one having n attributes will always defeat one with fewer than n. As long as it is remembered that speaking so is figurative, it does no harm. There is no reason to suppose that Spinoza ever forgot it, although he saw no reason to disturb the orthodox by reminding them of it. Hence when he writes that 'the more reality belongs to the nature of a thing, the more powers it has, of itself, to exist' (G II, 54/ 5-7), he should be read as figuratively declaring that, however many attributes there may be, the more nearly the number of an imagined substance's attributes approaches that number, the less it falls short of a maximally real substance that must be included in whatever is. And, since every attribute whatever independently constitutes the essence of a maximally real substance, his principle of plenitude may be formulated non-figuratively as what I shall call 'the principle of substance plenitude': namely, that any essence that is constituted by some attribute, as the essence of every substance is, must be constituted by every attribute.” [p.81-83)
In een volgend blog wil ik laten zien hoe Donagan 2/8 en 2/8s leest.