Combining Philosophers

All the ideas for Diogenes Laertius, Richard Cumberland and Michal Walicki

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32 ideas

2. Reason / A. Nature of Reason / 7. Status of Reason
6222 If a decision is in accord with right reason, everyone can agree with it [Cumberland]
2. Reason / C. Styles of Reason / 1. Dialectic
3035 Dialectic involves conversations with short questions and brief answers [Diog. Laertius]
4. Formal Logic / B. Propositional Logic PL / 1. Propositional Logic
17749 Post proved the consistency of propositional logic in 1921 [Walicki]
17765 Propositional language can only relate statements as the same or as different [Walicki]
4. Formal Logic / B. Propositional Logic PL / 3. Truth Tables
17764 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
17752 The empty set is useful for defining sets by properties, when the members are not yet known [Walicki]
17753 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
17759 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
17741 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
17747 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
17748 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
17761 A compact axiomatisation makes it possible to understand a field as a whole [Walicki]
17763 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
17758 Ordinals are transitive sets of transitive sets; or transitive sets totally ordered by inclusion [Walicki]
17755 Ordinals are the empty set, union with the singleton, and any arbitrary union of ordinals [Walicki]
17756 The union of finite ordinals is the first 'limit ordinal'; 2ω is the second... [Walicki]
17760 Two infinite ordinals can represent a single infinite cardinal [Walicki]
17757 Members of ordinals are ordinals, and also subsets of ordinals [Walicki]
6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry
17762 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
17754 Inductive proof depends on the choice of the ordering [Walicki]
10. Modality / A. Necessity / 2. Nature of Necessity
17742 Scotus based modality on semantic consistency, instead of on what the future could allow [Walicki]
13. Knowledge Criteria / A. Justification Problems / 2. Justification Challenges / a. Agrippa's trilemma
1816 Sceptics say demonstration depends on self-demonstrating things, or indemonstrable things [Diog. Laertius]
13. Knowledge Criteria / D. Scepticism / 1. Scepticism
1819 Scepticism has two dogmas: that nothing is definable, and every argument has an opposite argument [Diog. Laertius]
13. Knowledge Criteria / D. Scepticism / 6. Scepticism Critique
3064 When sceptics say that nothing is definable, or all arguments have an opposite, they are being dogmatic [Diog. Laertius]
14. Science / C. Induction / 4. Reason in Induction
3033 Induction moves from some truths to similar ones, by contraries or consequents [Diog. Laertius]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / d. Biological ethics
6217 Natural law is supplied to the human mind by reality and human nature [Cumberland]
22. Metaethics / B. Value / 1. Nature of Value / f. Ultimate value
6221 If there are different ultimate goods, there will be conflicting good actions, which is impossible [Cumberland]
22. Metaethics / C. The Good / 3. Pleasure / b. Types of pleasure
1838 Cyrenaic pleasure is a motion, but Epicurean pleasure is a condition [Diog. Laertius]
23. Ethics / A. Egoism / 1. Ethical Egoism
1769 Cynics believe that when a man wishes for nothing he is like the gods [Diog. Laertius]
23. Ethics / E. Utilitarianism / 1. Utilitarianism
6218 The happiness of individuals is linked to the happiness of everyone (which is individuals taken together) [Cumberland]
6220 The happiness of all contains the happiness of each, and promotes it [Cumberland]
25. Social Practice / D. Justice / 2. The Law / c. Natural law
6216 Natural law is immutable truth giving moral truths and duties independent of society [Cumberland]