From The Review of Metaphysics, 50 (September 1996), 63-77.
“Agents in this world determine the events in this world, together with
their definite ways of being . . . . But where are the agents that
define all the other ways things could have been, all the
hypothesized possible worlds?”
Why Possible Worlds Aren’t
W. Felt, S.J.
an uncommon argument for doubting the existence of possible worlds. It
calls into question the whole spectrum of supposed possible worlds, from
Lewis’s radically plural real worlds to the world-stories of Adams and
Plantinga. More than that, it challenges the tacit presuppositions of
most of those who have attacked such views. Yet despite its strangeness
I cannot but think this unorthodox position is correct. I shall furnish
metaphysical reasons for thinking that it is, and then proceed to show
why the possible worlds taken for granted in contemporary discussions
are based on a misconception, a metaphysical mistake that we would be
better off without.
this unusual claim on the ground of a metaphysics that is at odds with
the metaphysical viewpoint implied in the theories of possible worlds.
I suggest a different and, I think, superior way of conceiving the
world, experience, and what we mean by possibility.
faced here with the deliberate choice of philosophic first principles,
not with demonstrations proceeding from commonly acknowledged or even
tacitly presupposed principles. So there can be no knockdown argument
for such a choice, only reasons for thinking it better than its
alternatives. Lewis himself has noted that “one man’s reason is another
and, after arguing against “ersatz” substitutes for his thoroughgoing
modal realism, he advises: “Join the genuine modal realists; or foresake
genuine and ersatz worlds alike.”2
On the view that I shall propose, Lewis’s modal realism turns out to be
itself a reductio rather than a reason, and so I must set it
aside with all its variants, ersatz or otherwise.
Philosophic beginnings are chosen, but their consequences are not. As
Gilson put it: “Philosophers are free to lay down their own sets of
principles, but once this is done, they no longer think as they
wish-they think as they can.”3
These first principles are chosen not only for their initial
plausibility, but most importantly because they appear to make more
intelligible sense of experience than do their opposites. Consonance
with experience is the final criterion for accepting or rejecting any
philosophic standpoint. As Whitehead mentioned, it has been said that
systems of philosophy are never refuted, they are only abandoned, either
by reason of the mutual incoherence of their principles or because they
are inadequate to account for experience as we find it.4
this consideration, then, by recommending the plausibility of three
metaphysical principles that suggest themselves, both initially and in
their consequences, as characterizing our immediate, ongoing, changing
Principles of Becoming and Being.5
These principles are meant to express, at least partially, the character
of human experience viewed in terms of its changing patterns over time.
They link the dynamism of activity with its own formal patterns; they
link temporal actuality with possibility.
PRINCIPLE (A): Past actuality, whether immediate or remote, is
definite, exact, unambiguous.
Macbeth observed that what’s done cannot be undone. But also, what’s
done, being done, has its own definite character. Though knowledge of
the past fades, including knowledge of one’s own past self, this past is
not in itself ambiguous. We have to cope in the present with what has
in fact been decided, by us and by others, in the past. The pattern of
that past is settled, now and always. And how does this settled pattern
PRINCIPLE (B): Present actuality involves a process of determination
whereby from the indefiniteness of what might be (the range of
possibility), there is created the definiteness of what actually is
the writing of a philosophic essay. It is a process by which more
general initial thoughts take on the definition of exact formulation, a
process by which the vagueness of what might be written takes on the
definiteness of what is written. A more vivid analogy is that of a dune
buggy on a beach. The margin in which you can drive is perhaps already
determined by the surf on one side and sheer palisades on the other, so
that these two factors literally determine a range of possibility
for your driving. However, within that width you can drive (steer) as
you please, and it is just your activity of driving that determines the
track that you make in the sand. The definiteness, the pattern of that
track, is created precisely by your act of driving.
PRINCIPLE (C): Only actual events create this definiteness of settled
actuality within the given range of possibility.
Principle (C) is roughly the converse of Principle (B). (B) asserts
that actual events always exemplify, because they produce, definiteness,
an exact pattern of actuality. (C), on the other hand, asserts that
such definiteness requires actual events for its own creation. Of
itself the range of possibility leaves undetermined the particular
patterns that may be defined within it.
principle embodies the central point of controversy around which this
essay pivots. It is derived from reflection on our experience of the
creation of the patterns of ongoing temporal events. Thus the pattern of
tracks in the sand is created precisely, and only, by the driving, just
as the exact way in which you will walk through the next doorway will be
created precisely, and only, by your act of walking through it. The
act, by its very nature, creates its own pattern. Better, you by your
act of walking create the pattern.7
natural but further specification of Principle (C) there follows:
Corollary (1): In temporal events at least, the definiteness or
pattern of the event does not temporally precede the event itself.
what Henri Bergson meant by saying that the possible does not precede
reality is created as something unforeseeable and new [because
undefined), its image [its pattern of definiteness) is reflected
[mentally] behind it into the indefinite past; thus it finds that it has
from all time been possible, but it is at this precise moment [of
temporal creation) that it begins to have been always possible, and that
is why . . . its possibility, which does not precede its reality, will
have preceded it [for the mind] once the reality has appeared. The
possible is therefore the mirage of the present in the past.
viewpoint is so unusual and so critical to the argument of this essay
that it bears more illustration. Thus, the pattern of the actual track
in the sand had no existence in the world prior to the driving that made
the track. However, when we look at the track already made, we
naturally suppose that that pattern must have been possible even before
it was made—that it must have constituted a particular possibility
preceding the making of the track. We suppose that this particular
possibility was only one of an infinity of such possibilities awaiting
realization by the driving. Yet we make this supposition only by means
of mental rear-view mirrors. Only after the track is made do we have a
pattern to refer to and then to project mentally into the past as having
been antecedently possible.
almost impossible to exaggerate the seductiveness of this natural
tendency to relocate the present back into the past. Yet we deceive
ourselves when we suppose that the pattern in fact preexisted the
becomes more evident if we consider the production of a piece of
literature or of music. Mozart created the pattern of notes which is
his 40th symphony. Once created, this definite pattern can be thought
of as having always been possible—otherwise how could it have been
created at all? But only with the actual creative activity that went
into the composition of the symphony does there exist a pattern, a
single “possibility,” to talk about at all. Prior to its conception by
Mozart it was not, of course, impossible—that is, there were no
intrinsic impediments to its creation—yet there were no definite forms
at all, to be called possible or even impossible. There was literally
nothing specific to talk about or think about.9
think otherwise is to suppose that the exact pattern of notes which is
the 40th, existed as such, perfectly defined, in some ghostly limbo of
possibilities (one is reminded here of Quine’s “slum of possibles”),10
awaiting the infusion of actuality by Mozart. On such a view there
would never be artistic creation or novelty, only selection from among
pre given definite possibilities.
return finally to the dune buggy: according to the common way of
thinking of the possible and the real, there is an infinity of possible
tracks lying ahead on the beach, and, by your driving, you select one
for realization. This way of thinking implicitly likens the beach to a
railroad yard, where the locomotive enters upon one of several tracks
already laid down in advance. In fact, there are, however, no
preexistent possible tracks in the sand just because there is nothing to
define them ahead of time. Yet a single track does get created by the
actual driving. Only after the driving, however, is there a particular
track one can talk about or suppose, by hindsight, to have been possible
prior to its creation.
wording of Corollary (1) I added the qualification, “in temporal events
at least.” By this I meant that the form or pattern of an actual event
(its way of being or becoming) has no existence in time
prior to the event itself. Prior to the event its own form simply is
not, and (as Parmenides or even Wittgenstein would say) cannot even be
spoken of. This I consider an ineluctable conclusion if one takes
seriously that novelty does arise in the world. More than that: I now
propose to remove the above qualification, and to state, more broadly:
Corollary (2): No definiteness of form obtains at all, temporally or
atemporally, except in virtue of the activity of a real agent.
doubtless, is my most controversial claim. Yet given what I have
contended in justification of Corollary (1), it seems intuitively
plausible to make an analogous assertion concerning patterns of
definiteness (“possibles”) conceived just in themselves, apart from any
emergence in the temporal world. So conceived they are atemporal, not
of themselves involved in time. 11
examples of such pure patterns of possibility would be Plato’s Forms,
the possibilia of the medievals, and Whitehead’s “eternal
objects.”12 However, if
one accepts that a particular pattern of definiteness is realized (in
the literal sense: becomes part of a res) in temporal events only
as the result of the defining activity of an agent, it seems to me
reasonable to think that definite patterns of pure possibility, apart
from any temporal realization, also require the activity of a defining
agent. This seems more plausible than supposing that such distinct,
definite patterns simply exist, in their very distinctness,
within the general range of possibility.
noted that with regard to first principles, such as the above, there can
be no knockdown argument one way or another. Rather, we are at a level
at which we must in effect play philosophic cops and robbers. “Bang, I
got you!”“No, you missed me!” As the saying goes, you pays your money
and you takes your choice.
possible worlds aren’t.
Let us now apply the above principles to current notions of possible
worlds, and—because of its fundamentality and lucidity—first of all and
chiefly to the possible worlds of David Lewis. How does he conceive
possible worlds, and why does he think they exist? Here is his
believe that there are possible worlds other than the one we happen to
inhabit. If an argument is wanted, it is this. It is uncontroversially
true that things might be otherwise than they are I believe, and so do
you, that things could have been different in countless ways. But what
does this mean? Ordinary language permits the paraphrase: there are many
ways things could have been besides the way they actually are. On the
face of it, this sentence is an existential quantification. It says
that there exist many entities of a certain description, to wit “ways
things could have been.” I believe permissible paraphrases of what I
believe; taking the paraphrase at its face value, I therefore believe in
the existence of entities that might be called “ways things could have
been.” I prefer to call them “possible worlds.”13
years later, looking back at the controversies his view stirred up,
Lewis took pains to insist on the existential import of what he is
insist that my modal realism is simply the thesis that there are other
worlds, and individuals inhabiting those worlds; and that these are of a
certain nature, and suited to play certain theoretical roles. It is an
existential claim, not unlike the claim I would be making if I said that
there were Loch Ness monsters, or Red moles in the CIA, or
counterexamples to Fermat’s conjecture, or seraphim. It is not a thesis
about our semantic competence, or about the nature of truth, or about
bivalence, or about the limits of our knowledge. For me, the question
is of the existence of objects-not the objectivity of a subject matter.14
what Lewis claims; he does not pretend to be able to prove it, but
rather to offer plausible reasons why it is so. In On the Plurality
of Worlds he only argues that modal realism is useful, whereas in
the above argument from Counterfactuals he had made a stronger
claim. However, if the above principles are right, Lewis’s argument
runs right off the rails at its second step. That is where he supposes
that saying that “things might be otherwise than they are” is equivalent
to saying that “there are other ways things could have been.” The first
statement, however, reflects how the present state of affairs arose
within a general range of possibility set by its antecedents,
while the second statement posits the existence of a multiplicity of
distinct, particular possibilities, none of which has been
actualized by the course of events.
are not two different ways of saying the same thing; they are two
different statements altogether. To say that the track in the sand
could have had a different shape does not entitle one to say that there
exist other definite shapes that it could have had. What agency has
produced the definiteness of these supposed “other shapes” whereby we
may talk of them? And what agency has produced the definiteness of the
multiplicity of “other ways things could have been,” Lewis’s possible
worlds? Agents in this world determine the events in this world,
together with their definite ways of being, just as you, in your act of
walking, will determine the way in which you next walk through a
doorway. But where are the agents that define all the other ways things
could have been, all the hypothesized possible worlds? Lewis
tells us that he is making an existential claim about these possible
worlds. In his view there is the same existential definition to these
worlds as there is to the one we happen to inhabit, in which exactly
these and these events obtain and others do not. What can possibly be
the agent or agents that give their respective definitions to Lewis’s
plurality of possible worlds?
realists such as Lewis, however, would doubtless challenge the
presuppositions inherent in that question. They would say that I am
presupposing a distinction between the agents of this world and their
hypothetical (“counterpart”) agents in other possible worlds; that I am
attributing an ontic priority to the former; that I am making an
undemonstrable distinction between this real world and the other worlds
posited as possible, such that only agents of this (real) world are
really agents, in contrast to so-called but unreal agents of possible
willingly grant the accuracy of this charge but deny that it is a fault.
Cops and robbers. I think, though I cannot prove it, that a possible
or hypothetical or counterpart agent, simply is not an agent.16
I think, though I cannot prove it, that there is an ontological
difference as ways of being between possibility (I would rather
say potentiality) and actuality. Lewis, on the other hand,
writes: “Nor does this [actual] world differ from the others [other
possible worlds] in its manner of existing. I do not have the slightest
idea what a difference in manner of existing is supposed to be.”17
view here proposed, to be potentially is a real way of being that
differs essentially from being actually.18
But potentiality necessarily inheres in what is actual. Thus the range
of what is possible is determined by what is in fact actual, just as the
range for driving the dune buggy is set by the actuality of the cliffs
and the surf. Relations of possibility and necessity presuppose and
depend on what is actual.
Furthermore, potentiality as such cannot consist in a set, even an
infinite set, of distinct, definite possibilities. It is rather the
inherent capacity within given actuality for any such definite
possibilities to be realized by the activity of appropriate agents.
Potentiality as capacity differs ontologically from any set of forms of
definiteness that it makes possible. Hence to confuse possibility, as
potentiality, with a set of hypothesized possible patterns is to make a
category mistake. Furthermore, it leaves unanswered and unanswerable
how one is to account for the definite distinctness of the hypothesized
is a remarkably apposite passage in Aquinas in which St. Thomas not only
makes roughly the same point, but practically puts modern theories of
possible worlds into that perspective. In a digression in his
commentary on Aristotle’s treatise On Interpretation he writes:
are various opinions about possibility and necessity, about can be
and must be. Some people, like Diodorus, distinguish these by
reference to what happens, saying that can’t be never happens,
must be always happens, and can be sometimes happens, and
sometimes doesn’t. The Stoics, however, distinguished them by reference
to external obstruction, saying that the truth of must be can’t
be obstructed, of can’t be is always obstructed, and of can be
can sometimes be obstructed and sometimes not. Neither way of
distinguishing them seems adequate. The first way gets things back to
front: it is not that things must be because they always happen, but
that they always happen because they must be, and similarly for the
other definitions. And the second way appeals to something extrinsic and
so to speak inessential: it is not that things must be because nothing
obstructs them, but that nothing can obstruct them because they must be.19
extrapolation, Thomas would say that it is getting things backwards to
say that something is necessary because it is found in all possible
worlds (if there are any), rather than to say that some particular thing
is found in all possible worlds because it is necessary. Thomas
evidently takes possibility and necessity to reside primitively within
the relations of what is actual. Class inclusion is derivative from
those relations, not definitive of them.
am persuaded by the above principles, I must conclude that there can be
no possible worlds in the sense required by Lewis’s modal realism, for
there are no agents to produce the definiteness of their patterns.
Possible worlds, in his sense, cannot be existential objects as he
supposes; they can at most be his own conceptions of possible
other current conceptions of possible worlds—what Lewis calls “ersatz”
possible worlds? It will suffice here to examine one such conception,
for all of them suffer from the same defect. Lewis is right in
maintaining that genuine and ersatz possible worlds fall together, if
they fall at all.
consider in a general way the world-story or world book
interpretation of possible worlds suggested respectively by Robert
Merrihew Adams21 and Alvin
Plantinga. 22 Instead of
thinking of a possible world as another object like the real world, as
Lewis does, one can think of it as a set of propositions forming a story
or book describing a world. If a proposition can denote a state of
affairs, then suppose there exists a maximal, consistent set of
propositions describing a totality of states of affairs. It is maximal
in the sense that no further proposition can be added to it without
either duplicating or contradicting some proposition already contained
in it. One such world story will, furthermore, be distinctive, in that
all its propositions will in fact be true. That is, it alone will
describe the real world.
would be pointless here to review the alleged advantages of world-story
possible worlds over those of Lewis, for if the above principles are
sound it is evident that world-stories are as metaphysically specious as
are his. For world-stories are presumed to enjoy definiteness of and on
their own. The multiple—even infinite—possible world-stories are simply
taken as given in all their detail. Only on that supposition
does it make sense to distinguish one of them from another and to allege
that one has the distinction of being wholly true. Yet no agent can be
assigned that is capable of having made up the stories—at least no agent
short of God.23 Certainly
no human mind could invent the complete story of a universe.
again, then, I must conclude that there are in fact no existing possible
worlds for us to deal with, either genuine or ersatz, inasmuch as no
agent is available to have created their alleged definiteness.
however, shall we say about Lewis’s contention that a good reason for
thinking there are possible worlds is that it is useful to do so? Here
is how he puts it:
believe in a plurality of worlds?—Because the hypothesis is serviceable,
and that is a reason to think that it is true. The familiar analysis of
necessity as truth at all possible worlds was only the beginning. In
the last two decades, philosophers have offered a great many more
analyses that make reference to possible worlds, or to possible
individuals that inhabit possible worlds. I find that record most
impressive. I think it is clear that talk of possibilia has
clarified questions in many parts of the philosophy of logic, of mind,
of language, and of science—not to mention metaphysics itself.
spells out a number of such instances, and it is not possible here to
examine them individually. I submit, however, that in each case Lewis
fails to show that it is useful to think of possible worlds as
ontically existing, as modal realism asserts, rather than that
certain possibilities, or even vaguely defined possible worlds, are
simply conceived by us. Conceptions suffice in every case; there
is no need for autonomously existing possible worlds.
Conclusion: Possible Worlds and Platonism.
The Platonic method of philosophizing has been described by Pegis as
“the method of modeling the properties of existing beings on the
abstractions of the human intellect. In other words, it is the method
of thinking that being takes its characteristics as being from what it
reveals of itself in the state of being thought.”25
Pegis intended, and so do I, to distinguish Platonism from the
contrasting viewpoint of Aristotle or the adaptation made of it by
Aquinas, and I doubt that one could find a more striking example of
doing philosophy in the Platonic manner than the contemporary
possible-worlds ontologies, especially the modal realism of David Lewis.
Plato and Aristotle embodied the two fundamentally different ways of
regarding the world and of doing philosophy that characterize thinkers
in the whole course of Western philosophy. It is therefore illuminating
to set theories of possible worlds into this thematic and historical
context. I close this essay, then, by pointing to the Platonic strain
that is paramount in the ontologies of possible worlds.
of all, there is in Lewis’s thought an identification of definiteness
with actuality, and to make this identification is precisely to adopt
the Platonic viewpoint. The identification underlies his indexical
theory of what it means to be actual, so that the inhabitants of other
worlds, who are just as definite (and apparently just as active) as we,
are supposed to have as much right to call their worlds actual as we do
ours. For Lewis, all possible worlds are as real as our own, differing
only in their spatio-temporal locus; they do not differ in their manner
Lewis has in effect accepted the conclusion that Hartshorne reached,
that belief in possible worlds erases the distinction between the
possible and the actual. As Hartshorne put it: “One must admit that a
possible world is as definite and complex as the corresponding actual
one. This, I hold, reduces the distinction between possible and actual
to nullity. Value is in definiteness, and definiteness is the ‘soul of
actuality.’ Were possibility equally definite it would be redundant to
in Lewis’s argument for the existence of possible worlds, the conviction
that things could be otherwise becomes the conviction that there are
other ways things could have been. “Otherwise” has become “other ways,”
and that is exactly a Platonic move. Because we can conceive of other
ways, those other ways are assumed to be constitutive of extramental
regard, we may note the affinity between modal realism and the
quintessentially Platonic “ontological” argument for the existence of
God. When I conceive “that than which no greater can be conceived,” I
must ipso facto conceive “a necessarily existing being.”
Therefore such a being exists. This, however, slips in the tacit
assumption that what I have conceived in my mind has an extramental
counterpart, and that is 24 carat Platonism. Similarly Lewis, because
he conceives other ways of being, including other possible worlds,
habitually supposes that these other ways of being extramentally exist.
potentiality (or range of possibility inherent within given
actuality) becomes, for Lewis, possibilities, discrete, definite,
conceivable patterns of being. Aristotle’s dynamis, as a
manner of existing, has been replaced by an assemblage of
has passed from potentiality to patterns. But this is
retrogression beyond Aristotle to Parmenides. It renders impossible
Aristotle’s solution to Parmenides’ dilemma of becoming, for it denies
any intrinsic distinction as ways of existing between being actually
and being potentially.
same pattern of thinking is apparent in the way Lewis relates causality
to counterfactuals. He conceives that the way the letters appearing in
his book causally depend upon the keystrokes of his word processor is
just that if he had touched different keys, different characters
would have appeared. “That is how the letters depend causally upon
the keystrokes.”27 Thus
the causal power of actuality has passed into counterfactual patterns of
possibility. The attempt to describe causal relationships has left him
lost in the “woulds” of counterfactuals.
they are dark woulds indeed, since they do not in fact succeed in
describing causal power. They substitute instead a pattern of
conceived hypothetical possibilities. These possibilities are not only
purely conjectural, they even presuppose the causal power that they are
meant to define.28
Confiding to Dorothy why everything in Emerald City was green, Oz
explained: “When you wear green spectacles, why of course everything you
see looks green to you.”29
Everyone, I suppose, wears philosophic glasses of one prescription or
another, and Lewis has chosen to see everything through the lenses of
possible worlds. He admits that this entails a vast expenditure of
entitative suppositions, but nevertheless insists that the price is
argument of this essay implies that the price, far from being right, is
simply exorbitant. Possible worlds, in the currently accepted senses,
are the monstrous issue of a metaphysical mistake; they are unnecessary
for realizing the advantages Lewis seeks; and investing in them promotes
rampant metaphysical inflation at a time when the credibility of
philosophers’ currency is already badly undermined.
David Lewis, On the Plurality of Worlds (hereafter, OPW)
(New York: Basil Blackwell, 1986),207.
Lewis, OPW, 141.
Etienne Gilson, The Unity of Philosophical Experience
(Westminster, Md: Christian Classics 1982), 302-3.
Alfred North Whitehead, Process and Reality (hereafter, PR)
(New York: Free Press, 1978), 6.
I have proposed these principles elsewhere, especially in Making
Sense of Your Freedom: Philosophy for the Perplexed (Ithaca: Cornell
University Press, 1994),56, and in a complementary essay,
International Philoso-phical Quarterly 23 (1983): 251-65. They
amount to a reformulation of a fundamental conceptuality of Henri
Here I am using “actual” and “actuality” in a broader sense than does
Lewis, but the difference is irrelevant to this principle.
Principle (C) bears an obvious resemblance to Whitehead’s “ontological
principle” as described in his eighteenth Category of Explanation: “That
every condition to which the process of becoming conforms in any
particular instance has its reason either in the character of some
actual entity in the actual world of that concrescence, or in the
character of the subject which is in the process of concrescence. This
category of explanation is termed the ‘ontological principle.’ It
could also be termed the ‘principle of efficient, and final, causation’.
This ontological principle means that actual entities are the only
reasons; so that to search for a reason is to search for one or more
actual entities”; Whitehead, PR, 24.
Henri Bergson, “The Possible and the Real,” in The Creative Mind
(Totowa, N.J.: Littlefield, Adams, 1975)101.
If it is true that a Mozart can conceive in his mind an entire symphony,
and perhaps all at once, then I would grant that that conception
constitutes the definiteness of the symphony even prior to its being
written down or performed. The point is that the form of definiteness
had no existence prior to Mozart’s creative activity, whether that was
purely mental or also physical.
W. V. O. Quine, From a Logical Point of View (Cambridge: Harvard
University Press, 1953), 4.
This is not to say that they are omni-temporal, as if they existed at
all times, but rather that, precisely as patterns, they contain no
reference to temporal realization at all.
In a manner analogous to that of this essay, Lewis S. Ford has called
attention to the difficulty of reconciling Whitehead’s theory of eternal
objects with Whitehead’s own “ontological principle.” Ford elaborates
this difficulty and suggests an emendation of Whitehead’s metaphysics to
circumvent it. See Ford’s essay, “The Creation of ‘Eternal Objects,’”
The Modern Schoolman 71 (1994): 191-222.
David Lewis, Counterfactuals (Cambridge: Harvard University
Lewis, OPW, viii.
have avoided using the word “actual,” to which Lewis has attributed a
special meaning. As the reader probably knows, Lewis takes “actual” to
be an indexical term, like “here” or “now”—that is, as bearing an
implicit reference to the world of the speaker. Thus “actual” refers
exclusively to events taking place in the speaker’s own world. This
allows Lewis to deny any special priority to the world that we inhabit
since, as he says, inhabitants of other possible worlds have as much
right to refer to their own worlds as actual as we do to our own; see
Lewis, Counterfactuals, 85-6.
I have sketched some features of an appropriate theory of agency in
chapter 7 of my Making Sense of Your Freedom.
Lewis, OPW, 2.
Here and hereafter I decline to restrict the word “actual” to Lewis’s
Thomas Aquinas, “Commentary on Aristotle’s De Interpretatione,”
1.9 (18b26-19a22), in Aquinas: Selected Philosophical Writings,
trans. Timothy McDermott (Oxford: Oxford University Press, 1993), 277.
Nicholas Rescher comes close to this view when he insists that the human
mind plays an essential role in establishing possibilities. He writes:
“It is my central thesis that by the very nature of hypothetical
possibilities they cannot exist as such, but must be thought of: They
must be hypothesized, or imagined, or assumed, or something of this
sort”; Nicholas Rescher, “The Ontology of the Possible,” in The
Possible and the Actual, ed. Michael Loux (Ithaca; Cornell
University Press, 1979), 167. Yet he does not, I think, go far enough,
for he goes on to say that such a state of affairs need not actually be
conceived but must be conceivable; see ibid., 169. This appears to
assume an intrinsic definiteness of these possible objects of the mind
apart from their being actually conceived. If so, it violates the above
principles since it renders inexplicable the assumed definite-ness of
these unconceived but conceivable states of affairs.
See Robert Merrihew Adams, “Theories of Actuality” Nous 8 (1974):
Alvin Plantinga, The Nature of Necessity (Oxford: Clarendon
Press, 1974),45. ,
If one chose to introduce God for this purpose, as Leibniz seems to have
done, it would make God not only an agent but the sole agent. If it is
God who from eternity decides the definiteness of all actual events,
then there is no deciding left over for temporal agents. However, that
is just to deny, it seems to me, that there are any temporal agents at
all. The above principles presuppose creative, decision-making activity
on the part of temporal agents.
Lewis, OPW, 3.
Anton C. Pegis, ed., Introduction to Saint Thomas Aquinas (New
York: Modem Library, 1948), xviii.
Charles Hartshorne, Anselm’s Discovery (LaSalle, Ill.: Open
Court, 1965), 189-90.
Lewis, OPW, 23.
Compare in this regard the attempt sometimes made to define personal
freedom in terms of counterfactuals. Thus it is sometimes alleged that
to say “Mary acted freely” is just to say “If Mary had considered
different motives, she would have acted differently.” Counterfactuals
again, but to what purpose? Freedom is a characteristic of Mary’s act
itself, not of a set of hypothetical actions that Mary might have
performed. To suppose the latter would be to make a category mistake.
L. Frank Baum, The Wizard of Oz (Indianapolis: Bobbs-Merrill,
Posted April 2, 2009