Combining Texts

All the ideas for 'Locke on Human Understanding', 'First-order Logic, 2nd-order, Completeness' and 'On Freedom'

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21 ideas

5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Henkin semantics has a second domain of predicates and relations (in upper case) [Rossberg]
Second-order logic needs the sets, and its consequence has epistemological problems [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 / E. Nominalism / 2. Resemblance Nominalism
Two things can only resemble one another in some respect, and that may reintroduce a universal [Lowe]
9. Objects / B. Unity of Objects / 2. Substance / d. Substance defined
On substances, Leibniz emphasises unity, Spinoza independence, Locke relations to qualities [Lowe]
10. Modality / B. Possibility / 5. Contingency
Necessary truths can be analysed into original truths; contingent truths are infinitely analysable [Leibniz]
10. Modality / D. Knowledge of Modality / 2. A Priori Contingent
Only God sees contingent truths a priori [Leibniz]
10. Modality / E. Possible worlds / 3. Transworld Objects / e. Possible Objects
If non-existents are possible, their existence would replace what now exists, which cannot therefore be necessary [Leibniz]
12. Knowledge Sources / B. Perception / 6. Inference in Perception
Perception is a mode of belief-acquisition, and does not involve sensation [Lowe]
12. Knowledge Sources / B. Perception / 7. Causal Perception
Science requires a causal theory - perception of an object must be an experience caused by the object [Lowe]
16. Persons / D. Continuity of the Self / 1. Identity and the Self
Personal identity is a problem across time (diachronic) and at an instant (synchronic) [Lowe]
18. Thought / B. Mechanics of Thought / 4. Language of Thought
Mentalese isn't a language, because it isn't conventional, or a means of public communication [Lowe]
19. Language / A. Nature of Meaning / 2. Meaning as Mental
If meaning is mental pictures, explain "the cat (or dog!) is NOT on the mat" [Lowe]
28. God / A. Divine Nature / 3. Divine Perfections
God does everything in a perfect way, and never acts contrary to reason [Leibniz]