Combining Texts

All the ideas for 'Walking the Tightrope of Reason', 'Sense and Sensibilia' and 'Introduction to Mathematical Logic'

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42 ideas

1. Philosophy / D. Nature of Philosophy / 7. Despair over Philosophy
Philosophy may never find foundations, and may undermine our lives in the process [Fogelin]
2. Reason / A. Nature of Reason / 1. On Reason
Rationality is threatened by fear of inconsistency, illusions of absolutes or relativism, and doubt [Fogelin]
2. Reason / A. Nature of Reason / 9. Limits of Reason
Humans may never be able to attain a world view which is both rich and consistent [Fogelin]
A game can be played, despite having inconsistent rules [Fogelin]
2. Reason / B. Laws of Thought / 1. Laws of Thought
The law of noncontradiction is traditionally the most basic principle of rationality [Fogelin]
2. Reason / B. Laws of Thought / 3. Non-Contradiction
The law of noncontradiction makes the distinction between asserting something and denying it [Fogelin]
2. Reason / E. Argument / 3. Analogy
Legal reasoning is analogical, not deductive [Fogelin]
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]
7. Existence / D. Theories of Reality / 10. Vagueness / a. Problem of vagueness
Austin revealed many meanings for 'vague': rough, ambiguous, general, incomplete... [Austin,JL, by Williamson]
10. Modality / A. Necessity / 2. Nature of Necessity
Scotus based modality on semantic consistency, instead of on what the future could allow [Walicki]
10. Modality / C. Sources of Modality / 3. Necessity by Convention
Conventions can only work if they are based on something non-conventional [Fogelin]
12. Knowledge Sources / C. Rationalism / 1. Rationalism
My view is 'circumspect rationalism' - that only our intellect can comprehend the world [Fogelin]
13. Knowledge Criteria / A. Justification Problems / 1. Justification / c. Defeasibility
Knowledge is legitimate only if all relevant defeaters have been eliminated [Fogelin]
13. Knowledge Criteria / B. Internal Justification / 5. Coherentism / a. Coherence as justification
For coherentists, circularity is acceptable if the circle is large, rich and coherent [Fogelin]
13. Knowledge Criteria / C. External Justification / 6. Contextual Justification / a. Contextualism
A rule of justification might be: don't raise the level of scrutiny without a good reason [Fogelin]
13. Knowledge Criteria / D. Scepticism / 2. Types of Scepticism
Scepticism is cartesian (sceptical scenarios), or Humean (future), or Pyrrhonian (suspend belief) [Fogelin]
13. Knowledge Criteria / D. Scepticism / 6. Scepticism Critique
Scepticism deals in remote possibilities that are ineliminable and set the standard very high [Fogelin]
13. Knowledge Criteria / E. Relativism / 1. Relativism
Radical perspectivism replaces Kant's necessary scheme with many different schemes [Fogelin]
18. Thought / A. Modes of Thought / 5. Rationality / b. Human rationality
We are also irrational, with a unique ability to believe in bizarre self-created fictions [Fogelin]
21. Aesthetics / A. Aesthetic Experience / 3. Taste
Critics must be causally entangled with their subject matter [Fogelin]
21. Aesthetics / A. Aesthetic Experience / 4. Beauty
The word 'beautiful', when deprived of context, is nearly contentless [Fogelin]
21. Aesthetics / C. Artistic Issues / 5. Objectivism in Art
Saying 'It's all a matter to taste' ignores the properties of the object discussed [Fogelin]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / e. Human nature
Cynics are committed to morality, but disappointed or disgusted by human failings [Fogelin]
25. Social Practice / D. Justice / 3. Punishment / a. Right to punish
Deterrence, prevention, rehabilitation and retribution can come into conflict in punishments [Fogelin]
Retributivists say a crime can be 'paid for'; deterrentists still worry about potential victims [Fogelin]