Combining Texts

All the ideas for 'Confessions', 'Deflationary Metaontology of Thomasson' and 'Introduction to Mathematical Logic'

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43 ideas

4. Formal Logic / B. Propositional Logic PL / 1. Propositional Logic
Post proved the consistency of propositional logic in 1921 [Walicki]
Propositional language can only relate statements as the same or as different [Walicki]
4. Formal Logic / B. Propositional Logic PL / 3. Truth Tables
Boolean connectives are interpreted as functions on the set {1,0} [Walicki]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set
The empty set is useful for defining sets by properties, when the members are not yet known [Walicki]
The empty set avoids having to take special precautions in case members vanish [Walicki]
4. Formal Logic / F. Set Theory ST / 6. Ordering in Sets
Ordinals play the central role in set theory, providing the model of well-ordering [Walicki]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
To determine the patterns in logic, one must identify its 'building blocks' [Walicki]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A 'model' of a theory specifies interpreting a language in a domain to make all theorems true [Walicki]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
The L-S Theorem says no theory (even of reals) says more than a natural number theory [Walicki]
5. Theory of Logic / K. Features of Logics / 1. Axiomatisation
A compact axiomatisation makes it possible to understand a field as a whole [Walicki]
Axiomatic systems are purely syntactic, and do not presuppose any interpretation [Walicki]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / e. Ordinal numbers
Members of ordinals are ordinals, and also subsets of ordinals [Walicki]
Ordinals are the empty set, union with the singleton, and any arbitrary union of ordinals [Walicki]
The union of finite ordinals is the first 'limit ordinal'; 2ω is the second... [Walicki]
Two infinite ordinals can represent a single infinite cardinal [Walicki]
Ordinals are transitive sets of transitive sets; or transitive sets totally ordered by inclusion [Walicki]
6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry
In non-Euclidean geometry, all Euclidean theorems are valid that avoid the fifth postulate [Walicki]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / f. Mathematical induction
Inductive proof depends on the choice of the ordering [Walicki]
7. Existence / A. Nature of Existence / 2. Types of Existence
I prefer a lack of form to mean non-existence, than to think of some quasi-existence [Augustine]
7. Existence / D. Theories of Reality / 1. Ontologies
Three main questions seem to be whether a thing is, what it is, and what sort it is [Augustine]
9. Objects / A. Existence of Objects / 5. Individuation / e. Individuation by kind
No sortal could ever exactly pin down which set of particles count as this 'cup' [Schaffer,J]
9. Objects / F. Identity among Objects / 6. Identity between Objects
Identities can be true despite indeterminate reference, if true under all interpretations [Schaffer,J]
10. Modality / A. Necessity / 2. Nature of Necessity
Scotus based modality on semantic consistency, instead of on what the future could allow [Walicki]
12. Knowledge Sources / E. Direct Knowledge / 4. Memory
I can distinguish different smells even when I am not experiencing them [Augustine]
Mind and memory are the same, as shown in 'bear it in mind' or 'it slipped from mind' [Augustine]
Memory contains innumerable principles of maths, as well as past sense experiences [Augustine]
We would avoid remembering sorrow or fear if that triggered the emotions afresh [Augustine]
Why does joy in my mind make me happy, but joy in my memory doesn't? [Augustine]
15. Nature of Minds / A. Nature of Mind / 6. Anti-Individualism
Memory is so vast that I cannot recognise it as part of my mind [Augustine]
16. Persons / D. Continuity of the Self / 2. Mental Continuity / a. Memory is Self
Without memory I could not even speak of myself [Augustine]
16. Persons / F. Free Will / 6. Determinism / a. Determinism
If the future does not exist, how can prophets see it? [Augustine]
18. Thought / B. Mechanics of Thought / 5. Mental Files
Memories are preserved separately, according to category [Augustine]
22. Metaethics / C. The Good / 2. Happiness / c. Value of happiness
Everyone wants happiness [Augustine]
27. Natural Reality / D. Time / 1. Nature of Time / c. Idealist time
Maybe time is an extension of the mind [Augustine]
To be aware of time it can only exist in the mind, as memory or anticipation [Augustine, by Bardon]
27. Natural Reality / D. Time / 1. Nature of Time / g. Growing block
How can ten days ahead be a short time, if it doesn't exist? [Augustine]
27. Natural Reality / D. Time / 1. Nature of Time / h. Presentism
If the past is no longer, and the future is not yet, how can they exist? [Augustine]
27. Natural Reality / D. Time / 1. Nature of Time / i. Denying time
The whole of the current year is not present, so how can it exist? [Augustine]
27. Natural Reality / D. Time / 2. Passage of Time / a. Experience of time
I know what time is, until someone asks me to explain it [Augustine]
27. Natural Reality / D. Time / 2. Passage of Time / h. Change in time
I disagree with the idea that time is nothing but cosmic movement [Augustine]
27. Natural Reality / E. Cosmology / 3. The Beginning
Heaven and earth must be created, because they are subject to change [Augustine]
28. God / A. Divine Nature / 5. God and Time
If God existed before creation, why would a perfect being desire to change things? [Augustine, by Bardon]
If God is outside time in eternity, can He hear prayers? [Augustine]