[4.15.9] John Duns Scotus on Logical Possibility and Possible Worlds

John Duns Scotus (the “Subtle Doctor,” 1265/66–1308 AD), in “Ordinatio” writes about modal theory, logical possibility, and how these concepts influence the state of affairs in the world. According to his ideas:

  • God’s divine intellect includes all the simple notae, which are necessary and true propositions, like logical, mathematical, metaphysical truths.
  • Logical possibility is a non-repugnant or non-contradictory relation between two (or more) simple notae. E.g., the simple notae “animality” and “rationality” are non-repugnant since together define “man”.
  • The simple notae related by logical possibility are combined in the divine intellect in contingent divine ideas. E.g., “man”
  • Some divine ideas are necessary and true by definition; these are the necessary propositions. E.g., a priori truths, like “A triangle has three angles.” Others are contingent, with undefined truth value; these are contingent propositions.
  • The divine intellect presents the contingent propositions to the divine will, which decides for some of them by making them true, and with the same act creating them in the world. These are the true propositions. It is noteworthy that the freedom of the divine will is limited to the realm of the contingent propositions.
  • The maximal consistent collection of all the true propositions describes possible worlds, from which one is our real world.

The following OntoUML diagram presents Duns Scotus’s theory of logical possibility and possible worlds:

Duns Scotus’s theory of logical possibility and possible worlds

ClassDescriptionRelations
DivineIntellectGod’s intellect
DivineWill “The divine intellect presents these contingent propositions to the divine will as not yet having a truth value, and the divine will then (in a second instant of nature) contingently determines each to be true or be false.” (Normore, 2003)

“Since God’s [divine] will is the only root of contingency, it follows that ideas necessarily have their content and cannot ground a representation of contingent states of affairs. Conversely, suppose that God’s knowledge of future contingents were based on ideas, then he would not be omniscient, for he would know that Socrates could be either sitting or standing up at T, not that he is sitting at T. Finally, there would be no more difference between God’s knowledge of what is actual and of what is simply possible.” (Anfray 2014)
presents contingent propositions to DivineWill
SimpleNotae“The first stage is God’s natural knowledge of all necessary propositions. These are logically simples and are sometimes called by Scotus [simple] notae. Such notae are related to others according to repugnance or compossibility, independently of any power to bring them about. However, they are not self-subsistent entities, but are the products of God’s intellectual activity, which thus endows them with an ontological status, as intelligible beings. But the logical and modal properties of these entities are not constituted by God’s intellectual activity. Scotus summarizes this by claiming that the possibilia are formally such from themselves (formaliter ex se), but “principially” from God (principiative ab eo). All logical, mathematical, and metaphysical truths, in general all necessary truths, are known at precisely the instant when God produces, thinks things, and produces them in an esse intelligibile. Moreover, since the relations of compossibility [non-repugnance] and repugnance are independent from God’s intellectual activity, any modal truth is necessarily so. This entails that anything possible is necessarily possible.” (Anfray 2014) shared part of DivineIntelect Possibility and DivineIdea
LogicalPossiblityFor Scotus logical possibility is a fundamentally relational idea: “We can intelligibly speak of it only when we are dealing with several notae. Similarly, we can only ask whether notae are consistent when we are dealing with more than one. Thus, in the typical cases the question of whether some possible is possible of itself reduces to the question of the status of a relation among its metaphysical constituents: Are they related of themselves, and in what sense does that relation presuppose its relata?”
Simple notae are true and necessary.
relates between SimpleNotae; defines DivineIdea
Non-repugnance“Scotus articulated a notion of logical possibility as the nonrepugnance of terms and claimed that there is a real power corresponding to every logical possibility.” (Normore, 2003)

We can understand the concept of non-repugnance as the contratry of repugnence: the concept of ‘chimera’ is internally incoherent in the sense that the metaphysical constituents out of which the common nature of chimera would be composed (the notae) simply cannot be combined, and that is why there is a further repugnance between ‘chimera’ and ‘being something’. But this repugnance presupposes that ‘chimera’ is itself a complex term in which several notae are combined.Achimera is perhaps an animal with the head of a lion, the body of a goat, and the tail of a serpent. These notae are themselves complex and could be analyzed in the same way. On Scotus’s view, we eventually reach simple notae. Suppose we ask then whether all simple notae are possible – and further, whether they are possible of themselves.” (Normore, 2003)
characterizes LogicalPossibility
DivineIdea“According to Scotus, all combinations of compatible [non-repugnant] notae are objects of God’s knowledge, which he calls also [divine] ideas. Scotus is less explicit on the content of ideas than on their ontological status, but it is likely that an idea is an intellectual representation of any object, either of an individual like ‘Socrates’ or of a common nature like ‘man’ and that it contains everything that can be grasped by God through his intellect alone. An idea would be something like the deductive closure of all necessary truths concerning a given object. For instance, God’s intellect produces the notae of animality and rationality and these, being intrinsically nonrepugnant, can be combined in a single subject, man. And man can be combined with an individual differentia to produce a possible individual, say ‘Socrates.’ The idea of Socrates contains all the properties grounding necessary truths concerning him: that he is a man, that he is a rational animal, and that it is possible that he is sitting at T, and so on. However, it does not include the property of sitting at T, because it is a contingent truth. This leads Scotus to reject theories that ground God’s knowledge of future contingents on his ideas. First, they can ground only analytical, thus necessary truths. Moreover, ideas are intellectual representations, excluding any volitional element. They are therefore purely natural occurrences in God’s mind.” (Anfray 2014)
Necessary Proposition“Scotus has as a basic notion in his modal picture that of a nonepugnant collection of notae. Second, he claims that having thought the notae, the divine intellect naturally and in a single instant of nature considers all nonrepugnant combinations of them. Some of these combinations are such that it would be repugnant for their elements not to be so combined. These correspond to necessary propositions.” (Normore, 2003)
Necessary propositions are true and necessary.
subkind of DivineIdea; shared part of DescriptionOfPossibleWorld
ContingentProposition“Scotus has as a basic notion in his modal picture that of a nonepugnant collection of notae. Second, he claims that having thought the notae, the divine intellect naturally and in a single instant of nature considers all nonrepugnant combinations of them. […] Others are such that it is not repugnant for their elements either to be so combined or not. These correspond to contingent propositions.” (Normore, 2003)
Contingent propositions are contingent and have undifined truth value.
subkind of DivineIdea; shared part of DescriptionOfPossibleWorld
TrueProposition“The divine intellect presents these contingent propositions to the divine will as not yet having a truth value, and the divine will then (in a second instant of nature) contingently determines each to be true or be false. The divine will thus contingently determines a maximal consistent collection of contingent propositions to be true. Such a maximal consistent collection of [true] propositions is a description of (or, on some views, is) what both Leibniz and twentieth-century modal theorists would call a possible world.” (Normore, 2003)
True propositions contingent and true.
subkind of ContingentProposition; shared part of DescriptionOfPossibleWorld; defines and creates Thing
ThingAn object, a substance, a state of affairs in a possible world.exclusive part of PossibleWorld
DescriptionOfPossibleWorld “The divine will thus contingently determines a maximal consistent collection of contingent propositions to be true. Such a maximal consistent collection of [true] propositions is a description of (or, on some views, is) what both Leibniz and twentieth-century modal theorists would call a possible world.” (Normore, 2003) defines PossibleWorld
PossibleWorldA possible world, our world is an instance of that.

Sources

  • Normore, Calvin G., “Duns Scotus’s Modal Theory”, The Cambridge Companion to Duns Scotus, Cambridge University Press 2003, ed. Thomas Williams
  • Anfray, Jean-Pascal Anfray, “Molina and John Duns Scotus”, A Companion to Luis de Molina, Brill, 2014
  • Williams, Thomas, “John Duns Scotus“, The Stanford Encyclopedia of Philosophy (Winter 2019 Edition), Edward N. Zalta (ed.)

First published: 27/5/2021

[4.15.8] John Duns Scotus on Contingency of the Present and Free Will

John Duns Scotus (the “Subtle Doctor,” 1265/66–1308 AD), in “Quaestiones super libros Metaphysicorum Aristotelis”, “Lectura” and “Ordinatio” writes about modal theory, contingency of the present, and free will. His main ideas are:

  • He thinks, that modality (necessity and contingency) is not essentially connected to time.
  • The past is necessary, but contrary to the Aristotelian view (see [1.3.19]), the present is contingent, as the future is.
  • The present is contingent because, at a given time, we can have alternative open possibilities (potencies), all with the capacity to realize (actualize) in the instant of the present moment. In these cases, the present event is not necessarry because all the alternative possibilities could realize in the present instant. In these cases we don’t have an ordering in time of the potency and the actualized potency, but an ordering of instants of nature.
  • As a self-mover, the free will of the intelligent creature can pick one (or more) of the alternative possibilities and realize it in the present instant.

The following OntoUML diagram presents Duns Scotus’s theory of contingency of the present and free will.

Scotus on contingency of the present and free will
ClassDescriptionRelations
Time“In his Physics Aristotle defines time as the measure of change (kinesis) with respect to prior and posterior and defines change as the actualization of a potentiality as such.”
PastScotus accepts the necessity of the past.
“the past and future met in the present instant”
phase of Time
Present“He denies the same necessity to the present. […]
The present instant can, at a minimum, be regarded as a pair of instants of nature ordered as before and after in nature. […]
Scotus thinks that it is because of this ordering of nature within the present instant of time that we can speak of the present as being only contingently the way it is. It is as if the past and future met in the present instant with the prior instant of nature belonging to the past (as its endpoint) and the posterior one to the future (as its beginning).”
phase of Time
Future“the past and future met in the present instant”phase of Time
PotencyPotency in the Aristotelian sense (see [1.3.4]).
Example: “Consider a rational creature – an angel, for example – that exists only for an instant during which it is, let us suppose, loving God. The question posed is whether it could be loving God freely. The argument that the angel could not be loving God freely is that for it to do so it has to have a power [potency] to do otherwise, say, to hate God.”
prior to ActualizedPotency; is in Present
Not-actualizedPotencyNot-actualized potency, in the Aristotelian sense (see [1.3.4]) : a potency, which has not been realized.
Example: The angel does not hate God.
role of Potency
ActualizedPotencyActualized potency, in the Aristotelian sense (see [1.3.4]) : a potency, which has been realized.
Example: The angel loves God.
role of Potency; is in Present
OrderingOfInstants
OfNature
“not all causal relations (largely understood) involve succession in time. For Scotus the productive relations within the Trinity serve as obvious cases in which no temporal succession is involved, and the creation of the world (and with it motion and so time) is another. Even in natural philosophy the picture of light’s being propagated instantaneously through a diaphanous medium by the sun, a hypothesis certainly compatible with the empirical data available to Scotus, served as a case of a causal process in which the effect and the cause were coincident in time and in which, despite the temporal coincidence, there is a clear sense in which emission of light by the sun is prior to its reception on the earth. Now if one holds, as Scotus did, that in the relevant sense a power [potency] must be prior to its actualization (see In Metaph. 9, q. 14, for example) and one accepts the Propositio Famosa, one could generalize these examples to produce a partial ordering of instants of nature. A is naturally prior to B if and only if mention of A is required in giving an explanation of B. We can now give a sufficient condition for the distinctness of two instants of nature n1 and n2. […]”
Example: “In the context of the angel existing only for a single temporal instant, Scotus treats an instant of time as divisible into a sequence of instants of nature. […] The prior is that in which the angel has both the power [potency] to love God and the power to hate God, and the posterior is that in which the angel has actualized the power [potency] to love God. These are prior and posterior in nature because the power [potency] to love God is naturally prior to its actualization. Since ‘in’ the instant of time there is an instant of nature (namely the prior of the two) at which the angel has the power to hate God, we can say that the angel has the power [potency] to hate God at that instant of time (and could, relative to that ‘prior’ instant of nature, actualize it at the posterior instant of nature), and thus the angel is now free. [his will is free]”
relates Potency with ActualizedPotency
Creature’sWillCreature’s will “is the exercise of a rational power – that is, a power for opposites – that includes the ‘nonevident’ power for the contrary at time t of whatever it is actually choosing at time t.”
Example: “the angel could not be loving God freely is that for it to do so it has to have a power [power] to do otherwise, say, to hate God.”
recognizes Potency; decides for ActualizedPotency; is in Present
DecisionDecision of the Creature’sWill about the Potency to actualize. Relates Creature’sWill with ActualizedPotency
SelfMoverA creature’s (e.g. a human or an angel) will is a self mover, because it has “a power for opposites – that includes the ‘nonevident’ power for the contrary at time t of whatever it is actually choosing at time t.”
Example: The angel could love or hate God.
characterizes Creature’sWill

Sources

  • All citations from: Normore, Calvin G., “Duns Scotus’s Modal Theory”, The Cambridge Companion to Duns Scotus, Cambridge University Press 2003, ed. Thomas Williams
  • Williams, Thomas, “John Duns Scotus“, The Stanford Encyclopedia of Philosophy (Winter 2019 Edition), Edward N. Zalta (ed.)

First published: 20/5/2021