Sumários
Possible worlds (4)
23 Março 2023, 14:00 • Ricardo Santos
Possible worlds and quantification:
constant domain or variable domains? Undesirable consequences of the constant
domain. Plantinga’s two problems regarding variable domains. The debate between
necessitism (the view that [necessarily] everything necessarily exists) and
contingentism (the view that [possibly] something possibly does not exist).
Williamson’s argument for necessitism. Key role of the third premise, Objectual
Dependency (saying that a singular proposition ontologically depends on the
object it is about). Comparison with Plantinga’s argument from contingentism to
the denial of objectual dependency. Can we have both contingentism and
objectual dependency?
Possible worlds (3)
16 Março 2023, 14:00 • Ricardo Santos
Plantinga’s actualism, a moderate
form of modal realism. Two main claims: (i) everything is actual; (ii) possible
worlds are abstract objects. To simplify things, one can equate states of
affairs with propositions. Possible worlds are consistent and maximal sets of
propositions. Accounting for contingent existence by postulating variable
domains. Different truth conditions of “Possibly there are Fs” and “Some things
are possibly F”. Two problems: (1) Are there things that don’t exist? (2) Could
there be facts (true propositions) about things that don’t exist? Plantinga’s
solution in terms of individual essences (haecceities).
Possible worlds (2)
9 Março 2023, 14:00 • Ricardo Santos
Modal ambiguities: syntactic and
semantic. De dicto and de re modalities. Actualism and
possibilism. Lewis’s modal realism (cont.). Spatio-temporal individuation of
worlds. No overlap between worlds and no causal relations. Counterparts.
Promise of a reductive analysis of modality. Objections: irrelevance and
ontological extravagance.
Possible worlds (1)
2 Março 2023, 14:00 • Ricardo Santos
The widely spread use of possible
worlds in contemporary philosophy: in logic (truth-conditions for the modal
operators), epistemology (epistemic possibilities), philosophy of language
(propositions), metaphysics (properties and essences), philosophy of mind
(supervenience of the mental). Kinds of necessity and possibility. Introduction
to Lewis’s extreme modal realism: possible worlds as parallel concrete universes
(or spacetimes). Lewis’s indexical view of actuality.
Change (2)
23 Fevereiro 2023, 14:00 • Ricardo Santos
The problem of qualitative change
(continued). Critical discussion of relationism and perdurantism. Is there a
presentist solution to the problem of change? Presentism and the special theory
of relativity. Heller (1992)’s defense of temporal parts ontology against the
no-change objection.