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Single Idea 7682

[filed under theme 5. Theory of Logic / C. Ontology of Logic / 2. Platonism in Logic ]

Full Idea

At one level logic can be regarded as a theory of signs and formal rules, but we cannot neglect the meaning of propositions as they relate to states of affairs, and hence to possible properties and objects... there must be the possibility of truth-values.

Gist of Idea

Logic is not just about signs, because it relates to states of affairs, objects, properties and truth-values

Source

Dale Jacquette (Ontology [2002], Ch. 2)

Book Ref

Jacquette,Dale: 'Ontology' [Acumen 2002], p.44

A Reaction

Thus if you define logical connectives by truth tables, you need the concept of T and F. You could, though, regard those too as purely formal (like 1 and 0 in electronics). But how do you decide which propositions are 1, and which are 0?

The 22 ideas from 'Ontology'

7679 Ontology is the same as the conceptual foundations of logic [Jacquette]
7678 Ontology must include the minimum requirements for our semantics [Jacquette]
7683 Logic is based either on separate objects and properties, or objects as combinations of properties [Jacquette]
7684 Reduce states-of-affairs to object-property combinations, and possible worlds to states-of-affairs [Jacquette]
7691 The actual world is a consistent combination of states, made of consistent property combinations [Jacquette]
7688 The actual world is a maximally consistent combination of actual states of affairs [Jacquette]
7695 Do proposition-structures not associated with the actual world deserve to be called worlds? [Jacquette]
7687 Existence is completeness and consistency [Jacquette]
7692 Being is maximal consistency [Jacquette]
7689 The modal logic of C.I.Lewis was only interpreted by Kripke and Hintikka in the 1960s [Jacquette]
7681 Logic describes inferences between sentences expressing possible properties of objects [Jacquette]
7682 Logic is not just about signs, because it relates to states of affairs, objects, properties and truth-values [Jacquette]
7685 An object is a predication subject, distinguished by a distinctive combination of properties [Jacquette]
7697 On Russell's analysis, the sentence "The winged horse has wings" comes out as false [Jacquette]
7701 Can a Barber shave all and only those persons who do not shave themselves? [Jacquette]
7694 We must experience the 'actual' world, which is defined by maximally consistent propositions [Jacquette]
7703 If classes can't be eliminated, and they are property combinations, then properties (universals) can't be either [Jacquette]
7699 Numbers, sets and propositions are abstract particulars; properties, qualities and relations are universals [Jacquette]
7702 The extreme views on propositions are Frege's Platonism and Quine's extreme nominalism [Jacquette]
7706 If qualia supervene on intentional states, then intentional states are explanatorily fundamental [Jacquette]
7704 Reduction of intentionality involving nonexistent objects is impossible, as reduction must be to what is actual [Jacquette]
7707 To grasp being, we must say why something exists, and why there is one world [Jacquette]