Combining Texts

All the ideas for 'fragments/reports', 'Introduction to Mathematical Logic' and 'The Passions of the Soul'

expand these ideas     |    start again     |     specify just one area for these texts


28 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
Ordinals are transitive sets of transitive sets; or transitive sets totally ordered by inclusion [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]
Members of ordinals are ordinals, and also subsets of ordinals [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]
10. Modality / A. Necessity / 2. Nature of Necessity
Scotus based modality on semantic consistency, instead of on what the future could allow [Walicki]
17. Mind and Body / A. Mind-Body Dualism / 2. Interactionism
The pineal gland links soul to body, and unites the two symmetrical sides of the body [Descartes, by PG]
18. Thought / A. Modes of Thought / 3. Emotions / c. Role of emotions
For Descartes passions are God-given preservers of the mind-body union [Descartes, by Taylor,C]
18. Thought / A. Modes of Thought / 3. Emotions / e. Basic emotions
Are there a few primary passions (say, joy, sadness and desire)? [Descartes, by Cottingham]
There are six primitive passions: wonder, love, hatred, desire, joy and sadness [Descartes, by Goldie]
20. Action / B. Preliminaries of Action / 2. Willed Action / b. Volitionism
Merely willing to walk leads to our walking [Descartes]
22. Metaethics / B. Value / 2. Values / e. Death
We don't die because the soul departs; the soul departs because the organs cease functioning [Descartes]
23. Ethics / C. Virtue Theory / 3. Virtues / a. Virtues
Descartes makes strength of will the central virtue [Descartes, by Taylor,C]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / c. Ultimate substances
Pherecydes said the first principle and element is earth [Pherecydes, by Sext.Empiricus]
29. Religion / D. Religious Issues / 2. Immortality / a. Immortality
Pherecydes was the first to say that the soul is eternal [Pherecydes, by Cicero]