Combining Texts

All the ideas for 'The Character of Physical Law', 'First-order Logic, 2nd-order, Completeness' and 'Substance'

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28 ideas

1. Philosophy / D. Nature of Philosophy / 7. Despair over Philosophy
People generalise because it is easier to understand, and that is mistaken for deep philosophy [Feynman]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Second-order logic needs the sets, and its consequence has epistemological problems [Rossberg]
Henkin semantics has a second domain of predicates and relations (in upper case) [Rossberg]
There are at least seven possible systems of semantics for second-order logic [Rossberg]
5. Theory of Logic / B. Logical Consequence / 2. Types of Consequence
Logical consequence is intuitively semantic, and captured by model theory [Rossberg]
5. Theory of Logic / B. Logical Consequence / 3. Deductive Consequence |-
Γ |- S says S can be deduced from Γ; Γ |= S says a good model for Γ makes S true [Rossberg]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
In proof-theory, logical form is shown by the logical constants [Rossberg]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A model is a domain, and an interpretation assigning objects, predicates, relations etc. [Rossberg]
5. Theory of Logic / J. Model Theory in Logic / 2. Isomorphisms
If models of a mathematical theory are all isomorphic, it is 'categorical', with essentially one model [Rossberg]
5. Theory of Logic / K. Features of Logics / 4. Completeness
Completeness can always be achieved by cunning model-design [Rossberg]
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
A deductive system is only incomplete with respect to a formal semantics [Rossberg]
8. Modes of Existence / A. Relations / 4. Formal Relations / c. Ancestral relation
An ancestral relation is either direct or transitively indirect [Wiggins]
8. Modes of Existence / C. Powers and Dispositions / 4. Powers as Essence
Substances contain a source of change or principle of activity [Wiggins]
9. Objects / A. Existence of Objects / 5. Individuation / e. Individuation by kind
We never single out just 'this', but always 'this something-or-other' [Wiggins]
Sortal predications are answers to the question 'what is x?' [Wiggins]
A river may change constantly, but not in respect of being a river [Wiggins]
Sortal classification becomes science, with cross reference clarifying individuals [Wiggins]
If the kinds are divided realistically, they fall into substances [Wiggins]
'Human being' is a better answer to 'what is it?' than 'poet', as the latter comes in degrees [Wiggins]
Secondary substances correctly divide primary substances by activity-principles and relations [Wiggins]
9. Objects / B. Unity of Objects / 2. Substance / d. Substance defined
We refer to persisting substances, in perception and in thought, and they aid understanding [Wiggins]
9. Objects / C. Structure of Objects / 3. Matter of an Object
Matter underlies things, composes things, and brings them to be [Wiggins]
14. Science / D. Explanation / 2. Types of Explanation / k. Explanations by essence
The category of substance is more important for epistemology than for ontology [Wiggins]
Naming the secondary substance provides a mass of general information [Wiggins]
15. Nature of Minds / C. Capacities of Minds / 4. Objectification
Seeing a group of soldiers as an army is irresistible, in ontology and explanation [Wiggins]
26. Natural Theory / D. Laws of Nature / 4. Regularities / a. Regularity theory
Physical Laws are rhythms and patterns in nature, revealed by analysis [Feynman]
27. Natural Reality / B. Modern Physics / 2. Electrodynamics / d. Quantum mechanics
Nobody understands quantum mechanics [Feynman]
27. Natural Reality / C. Space / 3. Points in Space
We should regard space as made up of many tiny pieces [Feynman, by Mares]