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TI/Boer: Thesis: Believe as a 2-digit relation to a special kind of property ("thought content"). Spelling: German writing (fracture).
Stock: Relation theory: Boer pro: belief as a relation to thought content (certain property)
STI/Boer: Semantics for belief attribution, which considers substitutional opacity in belief reports as a genuine semantic feature.
Thesis: these two together solve many known puzzles.
Object-dependent senses/Frege/Boer: these are to be defended here (Boer pro Frege).
Participating/Participation/Boer: a thing that does not participate in the world is either e.g. a non-existent thing or a non-space-time individual, a non-existent or false proposition, a non-existent or non-persisting state, a non-existent or unexplained property or relation, or a non-existent or non-occurring event.
So more precisely:
(D2) R is a participation-independent relation = it is possible for an existing thing to have a relation R to a thing that does not participate in the world.
E.g. mental reference: would then be intentional simply because one can think of abstract as well as of concrete individuals (also unexemplified properties, etc.).
Relation/Participation/Boer: although a tolerant actualist who acknowledges the existence of relations at all, accepts that some relations are participation-independent, the relation of such relations is not limited to existing things.
(D2) only requires that an existing thing has such a relation to a non-participating thing.
Relation R: from the fact that someone has R to something does not follow that this something participates in the world ((s) one can think of abstract objects).
Non-existence: if there are non-existent things, there is nothing in (D2) that forbids one to have a participation-independent relation like mental reference to them. ((s One can think of something non-existent) That at most will be rejected by a very strict nominalism.
N: be an entity of a given type
(E: spelling in the book: black letter)
EN: be the essential property of things of this type N iff
i) EN can be exemplified (i.e., that there may be such a thing)
ii) necessary: a thing exemplifies EN iff it is identical to N.
Haecceitas: of N. the property to be N. This would be trivially the essence of N.
Definition normal/terminology/Boer: if we wanted to name things for which it is possible that they exist/that they are actual.
Definition abstract/terminology/Boer: be a thing for which it is not possible that it exists/is actual.
a) in the first sense: (mere Possibilia): normal, if non-existent.
b) as essentially fictional: abstract.
Steven E. Boer
Thought-Contents: On the Ontology of Belief and the Semantics of Belief Attribution (Philosophical Studies Series) New York 2010
Steven E. Boer
Knowing Who Cambridge 1986