Combining Texts

All the ideas for 'Disputationes metaphysicae', 'On Second-Order Logic' and 'Identity'

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32 ideas

5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
14249 Boolos reinterprets second-order logic as plural logic [Boolos, by Oliver/Smiley]
10830 Second-order logic metatheory is set-theoretic, and second-order validity has set-theoretic problems [Boolos]
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
10829 A sentence can't be a truth of logic if it asserts the existence of certain sets [Boolos]
5. Theory of Logic / G. Quantification / 2. Domain of Quantification
10832 '∀x x=x' only means 'everything is identical to itself' if the range of 'everything' is fixed [Boolos]
5. Theory of Logic / K. Features of Logics / 4. Completeness
10834 Weak completeness: if it is valid, it is provable. Strong: it is provable from a set of sentences [Boolos]
5. Theory of Logic / K. Features of Logics / 6. Compactness
13841 Why should compactness be definitive of logic? [Boolos, by Hacking]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / c. Counting procedure
16014 It is controversial whether only 'numerical identity' allows two things to be counted as one [Noonan]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / e. Peano arithmetic 2nd-order
10833 Many concepts can only be expressed by second-order logic [Boolos]
8. Modes of Existence / B. Properties / 8. Properties as Modes
16665 There are entities, and then positive 'modes', modifying aspects outside the thing's essence [Suárez]
16666 A mode determines the state and character of a quantity, without adding to it [Suárez]
9. Objects / B. Unity of Objects / 2. Substance / a. Substance
16667 Substances are incomplete unless they have modes [Suárez, by Pasnau]
9. Objects / C. Structure of Objects / 2. Hylomorphism / a. Hylomorphism
17007 Forms must rule over faculties and accidents, and are the source of action and unity [Suárez]
9. Objects / C. Structure of Objects / 2. Hylomorphism / d. Form as unifier
16780 Partial forms of leaf and fruit are united in the whole form of the tree [Suárez]
16758 The best support for substantial forms is the co-ordinated unity of a natural being [Suárez]
9. Objects / C. Structure of Objects / 4. Quantity of an Object
16743 We can get at the essential nature of 'quantity' by knowing bulk and extension [Suárez]
9. Objects / D. Essence of Objects / 14. Knowledge of Essences
16742 We only know essences through non-essential features, esp. those closest to the essence [Suárez]
9. Objects / E. Objects over Time / 4. Four-Dimensionalism
16024 I could have died at five, but the summation of my adult stages could not [Noonan]
9. Objects / E. Objects over Time / 5. Temporal Parts
16023 Stage theorists accept four-dimensionalism, but call each stage a whole object [Noonan]
9. Objects / F. Identity among Objects / 1. Concept of Identity
22143 Identity does not exclude possible or imagined difference [Suárez, by Boulter]
22144 Real Essential distinction: A and B are of different natural kinds [Suárez, by Boulter]
22146 Minor Real distinction: B needs A, but A doesn't need B [Suárez, by Boulter]
22145 Major Real distinction: A and B have independent existences [Suárez, by Boulter]
22147 Conceptual/Mental distinction: one thing can be conceived of in two different ways [Suárez, by Boulter]
22148 Modal distinction: A isn't B or its property, but still needs B [Suárez, by Boulter]
9. Objects / F. Identity among Objects / 2. Defining Identity
16015 Problems about identity can't even be formulated without the concept of identity [Noonan]
16017 Identity is usually defined as the equivalence relation satisfying Leibniz's Law [Noonan]
16016 Identity definitions (such as self-identity, or the smallest equivalence relation) are usually circular [Noonan]
16020 Identity can only be characterised in a second-order language [Noonan]
9. Objects / F. Identity among Objects / 8. Leibniz's Law
16018 Indiscernibility is basic to our understanding of identity and distinctness [Noonan]
16019 Leibniz's Law must be kept separate from the substitutivity principle [Noonan]
10. Modality / D. Knowledge of Modality / 4. Conceivable as Possible / a. Conceivable as possible
22149 Scholastics assess possibility by what has actually happened in reality [Suárez, by Boulter]
29. Religion / B. Monotheistic Religion / 4. Christianity / c. Angels
16682 Other things could occupy the same location as an angel [Suárez]