Combining Texts

All the ideas for 'fragments/reports', 'The Origin of Forms and Qualities' and 'Introduction to Mathematical Logic'

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30 ideas

2. Reason / D. Definition / 4. Real Definition
Essential definitions show the differences that discriminate things, and make them what they are [Boyle]
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
Ordinals are transitive sets of transitive sets; or transitive sets totally ordered by inclusion [Walicki]
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]
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]
8. Modes of Existence / C. Powers and Dispositions / 1. Powers
Boyle attacked a contemporary belief that powers were occult things [Boyle, by Alexander,P]
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / a. Dispositions
In the 17th century, 'disposition' usually just means the spatial arrangement of parts [Boyle, by Pasnau]
9. Objects / C. Structure of Objects / 2. Hylomorphism / a. Hylomorphism
Form is not a separate substance, but just the manner, modification or 'stamp' of matter [Boyle]
To cite a substantial form tells us what produced the effect, but not how it did it [Boyle]
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 / B. Perception / 2. Qualities in Perception / d. Secondary qualities
Boyle's term 'texture' is not something you feel, but is unobservable structures of particles [Boyle, by Alexander,P]
Boyle's secondary qualities are not illusory, or 'in the mind' [Boyle, by Alexander,P]
13. Knowledge Criteria / E. Relativism / 2. Knowledge as Convention
By nature people are close to one another, but culture drives them apart [Hippias]
14. Science / D. Explanation / 2. Types of Explanation / i. Explanations by mechanism
Explanation is deducing a phenomenon from some nature better known to us [Boyle]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / g. Atomism
The corpuscles just have shape, size and motion, which explains things without 'sympathies' or 'forces' [Boyle, by Alexander,P]
26. Natural Theory / A. Speculations on Nature / 7. Later Matter Theories / b. Corpuscles
The corpuscular theory allows motion, but does not include forces between the particles [Boyle, by Alexander,P]