Sumários
Causation (1)
23 Abril 2026, 14:00 • Ricardo Santos
Why is causation important. Hume’s regularity theory of causation. Hume’s negative argument (for the claim that causation is not necessary connection). Hume’s alternative analysis in terms of temporal priority, contiguity and constant conjunction. Hume’s explanation for the mistaken belief that causation involves necessary connection in terms of habit and expectation. Problems for the regularity theory. How to distinguish accidental from causal regularities? How to explain exceptions to causal regularities? How to account for unique case causal relations? Mackie’s analysis of causation in terms of INUS conditions. Critical discussion. An argument to the effect that US (unnecessary but sufficient) conditions are arbitrarily long and never fully specifiable. Skepticism about US conditions.
Possible worlds (4)
16 Abril 2026, 14:00 • Ricardo Santos
Plantinga’s actualism (continued). Accounting for contingent existence
by postulating variable domains. How to evaluate propositions about an object x
in a world w in which x does not exist? Can there be such propositions in w? Actualism
versus possibilism: disagreement about the existence of merely possible objects
(i.e. things that do not exist in the actual world but exist in other possible
worlds). Plantinga’s solution in terms of individual essences. Williamson’s
defense of the objectual dependency of propositions and argument for necessitism
(the view that necessarily everythings necessarily exists). Proposed distinction
between existing and being concrete.
Possible worlds (3)
9 Abril 2026, 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. Necessary and contingent truths explained as propositions included in all or only some worlds. Accounting for contingent existence by postulating variable domains.
Possible worlds (2)
26 Março 2026, 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)
19 Março 2026, 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.