[6.6.1] Pierro Pomonazzi on Miracles

Pietro Pomponazzi (1462–1525) in the work On Incantations, “undermines the use of demonic and supernatural explanations for sublunary phenomena”.

  • Particulars can be: natural and preternatural particulars
  • Demons are subkind of preternatural particular
  • Manifest cause; occult power; and indirect cause are behind the causes of wondrous effects
  • Demon’s knowledge is a component demon
  • Human knowledge is subkind of demon’s knowledge and the component of a particular human
  • Sublunary particulars are earthly objects.
  • Natural particulars are celestial and sublunary bodies.

The following OntoUML diagram shows the main structure of Pomponazzi’s model:

Pomonazzi on miracles
ParticularA particular
PreternaturalParticularThe work is presented as a response to the question: How would Aristotelians explain what “seems to be beyond the order of nature” (praeter nature ordinem) or, in other words, what seems preternatural? The category of preternatual, which included diseases and strange, seemingly irregular phenomena, formed the subject matter of numerous early modern philosophical inquiries (see Daston 2000)subkind of Particular
Demon“Yet, Pomponazzi contended that Aristotelians should not use demons to explain these wondrous events. In Pomponazzi’s view even if demons exist, a premise that Aristotle did not admit according to Pomponazzi’s interpretation of Metaphysics Lambda, they would not be able to affect the sublunary world because they would not have adequate knowledge of its particulars.”subkind of Preternatural Particular
HumanKnowledgeHuman knowledge
Demon’sKnowledgeDemons’ knowledge of sublunary particulars must derive either through essences or from sensation and phantasmata (i.e., mental images). Knowledge through essences, however, does not provide knowledge of singulars but only universals and species. Moreover, knowledge from sensation and phantasmata entails generation, corruption, and corporeality, properties which cannot belong to demons (1.1). […]
Demons’ lack of knowledge of natural particulars is merely one reason they cannot be the cause of wondrous sublunary events. Citing Augustine, Pomponazzi contended that all theologians hold that while demons can directly move bodies from one place to another they cannot alter them directly but must do so through natural bodies. Yet, Pomponazzi rejected the likelihood that demons affect change by applying active powers to passives, just like humans imperfectly do when they apply medicines. For Pomponazzi, this understanding of demonic action is untenable because it requires that demons use sensible material substances, which would be detectable. Presumably demons must carry these substances in pillboxes and bags, all of which is contrary to experience (1.2). Finally, he concluded that it is superfluous to suppose demonic influence “because we can save these kinds of experiences through natural causes” (1.3). Accordingly, the first half of On Incantations posits hypothetical natural causes of preternatural experiences in an attempt to show the inadequacy and superfluity of demonic explanation. Pomponazzi presented his conclusions as part of a process that leads closer to the truth, arguing that “sciences develop through steps” (scientiae enim fiunt per additamenta) (9.1). He likened this process to changes in legal codes, whereby better laws replace older inferior ones, admitting that his solutions should be accepted only while there are no preferable alternatives (Peroratio.1).”
subkind of HumanKnowedge
CauseOfWondrousEffectsThree causes of wondrous effects: “Employing doctrines key to natural magic, Pomponazzi put forth three potential ways that natural causes could explain wondrous effects”characterizes Preternatural Particular
ManifestCause; OccultPower;
Employing doctrines key to natural magic, Pomponazzi put forth three potential ways that natural causes could explain wondrous effects:
directly through manifest causes, such as heat and cold; through occult qualities or powers; or indirectly [indirect causes] through vapors and spirits that had been altered by such powers (3.1–3; Copenhaver 2015: 272–84). In support of these explanations, citing Albertus Magnus, Marsilio Ficino, Pliny, and unnamed botanists, he maintained that herbs, stones, minerals, and animal extracts possess nearly countless occult powers and that if we knew them it would be possible to reduce those effects that the unlearned attribute to demons and angels to the actions of these occult powers. In support of the existence of these occult powers Pomponazzi described experiences with herbal medicines, magnets, electric rays (torpedines), and remoras—fish that allegedly could halt ships with the power of their mouths—experiences, all verified as true by respected authorities (3.2–3). […]
Applying these causes, Pomponazzi explained that many of those accused
of necromancy, like the medieval physicians and astrologers Pietro d’Abano and Cecco d’Ascoli, were merely very knowledgeable and capable of applying actives to passives (4.1). Moreover, it is possible that some humans possess extraordinary occult powers that allow them to affect cures through touch, like the kings of France, or to perform other marvelous feats such as charming snakes and opening doors without touching them (4.2). 
Pomponazzi argued that the powers of imagination can produce real effects. For example, he cited the widespread belief that women’s thoughts at the time of conception will produce a fetus that is similar to those thoughts.
Therefore, the power of fascination and imaginative powers transmitted
through vapors might explain unexpected cures and diseases just as
they are supposedly responsible for the spread of leprosy and plague”
subkind of CauseOfWondrousEffects
NaturalParticularNatural particulars are celestial and sublunary bodies.subkind of Particular
SublunaryParticularA particular sublunary body is an earthly object.subkind of NaturalParticular
ParticularHumanA particular humansubkind of SublunaryParticular


  • Martin, Craig, “Pietro Pomponazzi“, The Stanford Encyclopedia of Philosophy (Winter 2021 Edition), Edward N. Zalta (ed.).

First published: 05/11/2022

[5.0.1] John Philoponus on Place, Space, and Impetus

John Philoponus (490-570 AD) altered the classical Aristotelian theory in some relevant aspects:

  • Length, breadth, and depth are dimensions
  • Place and space are three-dimensional extensions
  • Substance relates to space
  • Substance relates to the impetus
  • Impetus is a kind of energeia

The following OntoUML diagram presents the theory of impetus and space

John Philoponus on place, space and impetus
Place“Aristotle defined the pace of a body as the inner surface of the body or all the bodies taken together that contain it (Phys. IV 4); Philoponus replies that place ought instead to be conceived as the three-dimensional extension identical to the determinate size of the given body, i.e. its volume.” subkind of
Spacespace as a whole is the indeterminate three-dimensional extension everywhere devoid of body, though it is not actually infinite – so much Philoponus concedes to Aristotle. Philoponus’ discussion of matter builds upon this conception of space. […] However, in Book XI of the polemical treatise against Proclus (see below, 3.1) he jettisons the Neoplatonic conception of prime matter and posits as the most fundamental level of his ontology ‘the three-dimensional’, as he calls it, i.e. indeterminately extended mass.
[…] following the Stoics (Aet. 414), and it has been pointed out that this ontological level is reminiscent to us of the Cartesian res extensa, although Descartes would not allow Philoponus’ distinction between space and corporeal extension. In order to rebuff the likely objection that ’the three-dimensional’ cannot be the most fundamental level of being because extension, belonging to the Aristotelian category of quantity, is an accident and requires the assumption of a distinct underlying subject, Philoponus argues that extension is in fact not an accident, but an essential and inseparable differentia of ‘the three-dimensional’, just like heat in fire or whiteness in snow. Thus quantity (corporeal extension) is constitutive of the body as such. This amounts to a promotion of one sort of quantity to the category of substance.”
subkind of
DimensionLength, breath, and depth are dimensions
Length, Breadth, DepthLength, breadth, and depth are dimensionssubkind of
Substance “Thus quantity (corporeal extension) is constitutive of the body as such. This amounts to a promotion of one sort of quantity to the category of substance.
Impetus“Philoponus compares this impetus or ‘incorporeal motive 
enérgeia’, as he calls it, to the activity earlier attributed to light.
Once projectile motion was understood in terms of an impetus in this way, it became possible for Philoponus to reassess the rôle of the medium: far from being responsible for the continuation of a projectile’s motion it is in fact an impediment to it (In Phys. 681). On this basis Philoponus concludes, against Aristotle, that there is in fact nothing to prevent one from imagining motion taking place through a void.”
subkind of
Enérgeia“Philoponus compares this impetus or ‘incorporeal motive enérgeia, as he calls it, to the activity earlier attributed to light.”


  • Wildberg, Christian, “John Philoponus”The Stanford Encyclopedia of Philosophy (Winter 2021 Edition, Edward N. Zalta (ed.)
  • First published: 16/5/2022