Combining Texts

All the ideas for 'Logical Consequence', 'Which Logic is the Right Logic?' and 'The Gay (Joyful) Science'

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


57 ideas

1. Philosophy / F. Analytic Philosophy / 5. Linguistic Analysis
Grammar only reveals popular metaphysics [Nietzsche]
3. Truth / A. Truth Problems / 3. Value of Truth
Is the will to truth the desire to avoid deception? [Nietzsche]
4. Formal Logic / A. Syllogistic Logic / 2. Syllogistic Logic
'Equivocation' is when terms do not mean the same thing in premises and conclusion [Beall/Restall]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
The axiom of choice now seems acceptable and obvious (if it is meaningful) [Tharp]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
Logic is either for demonstration, or for characterizing structures [Tharp]
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
Formal logic is invariant under permutations, or devoid of content, or gives the norms for thought [Beall/Restall]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
Elementary logic is complete, but cannot capture mathematics [Tharp]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Second-order logic isn't provable, but will express set-theory and classic problems [Tharp]
5. Theory of Logic / B. Logical Consequence / 2. Types of Consequence
Logical consequence needs either proofs, or absence of counterexamples [Beall/Restall]
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
Logical consequence is either necessary truth preservation, or preservation based on interpretation [Beall/Restall]
5. Theory of Logic / B. Logical Consequence / 8. Material Implication
A step is a 'material consequence' if we need contents as well as form [Beall/Restall]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / b. Basic connectives
In sentential logic there is a simple proof that all truth functions can be reduced to 'not' and 'and' [Tharp]
5. Theory of Logic / G. Quantification / 2. Domain of Quantification
The main quantifiers extend 'and' and 'or' to infinite domains [Tharp]
5. Theory of Logic / G. Quantification / 7. Unorthodox Quantification
There are at least five unorthodox quantifiers that could be used [Tharp]
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
A 'logical truth' (or 'tautology', or 'theorem') follows from empty premises [Beall/Restall]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
Models are mathematical structures which interpret the non-logical primitives [Beall/Restall]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
Skolem mistakenly inferred that Cantor's conceptions were illusory [Tharp]
The Löwenheim-Skolem property is a limitation (e.g. can't say there are uncountably many reals) [Tharp]
5. Theory of Logic / K. Features of Logics / 3. Soundness
Soundness would seem to be an essential requirement of a proof procedure [Tharp]
5. Theory of Logic / K. Features of Logics / 4. Completeness
Completeness and compactness together give axiomatizability [Tharp]
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
If completeness fails there is no algorithm to list the valid formulas [Tharp]
5. Theory of Logic / K. Features of Logics / 6. Compactness
Compactness is important for major theories which have infinitely many axioms [Tharp]
Compactness blocks infinite expansion, and admits non-standard models [Tharp]
5. Theory of Logic / K. Features of Logics / 8. Enumerability
A complete logic has an effective enumeration of the valid formulas [Tharp]
Effective enumeration might be proved but not specified, so it won't guarantee knowledge [Tharp]
6. Mathematics / B. Foundations for Mathematics / 2. Proof in Mathematics
Hilbert proofs have simple rules and complex axioms, and natural deduction is the opposite [Beall/Restall]
7. Existence / A. Nature of Existence / 3. Being / c. Becoming
We Germans value becoming and development more highly than mere being of what 'is' [Nietzsche]
10. Modality / A. Necessity / 2. Nature of Necessity
Necessity is thought to require an event, but is only an after-effect of the event [Nietzsche]
11. Knowledge Aims / A. Knowledge / 1. Knowledge
The strength of knowledge is not its truth, but its entrenchment in our culture [Nietzsche]
12. Knowledge Sources / B. Perception / 1. Perception
We became increasingly conscious of our sense impressions in order to communicate them [Nietzsche]
13. Knowledge Criteria / B. Internal Justification / 2. Pragmatic justification
We have no organ for knowledge or truth; we only 'know' what is useful to the human herd [Nietzsche]
13. Knowledge Criteria / E. Relativism / 1. Relativism
We assume causes, geometry, motion, bodies etc to live, but they haven't been proved [Nietzsche]
13. Knowledge Criteria / E. Relativism / 3. Subjectivism
Nietzsche's perspectivism says our worldview depends on our personality [Nietzsche, by Fogelin]
It would be absurd to say we are only permitted our own single perspective [Nietzsche]
15. Nature of Minds / B. Features of Minds / 1. Consciousness / d. Purpose of consciousness
All of our normal mental life could be conducted without consciousness [Nietzsche]
Only the need for communication has led to consciousness developing [Nietzsche]
15. Nature of Minds / B. Features of Minds / 1. Consciousness / e. Cause of consciousness
Only our conscious thought is verbal, and this shows the origin of consciousness [Nietzsche]
15. Nature of Minds / B. Features of Minds / 2. Unconscious Mind
Most of our lives, even the important parts, take place outside of consciousness [Nietzsche]
Whatever moves into consciousness becomes thereby much more superficial [Nietzsche]
16. Persons / C. Self-Awareness / 3. Limits of Introspection
'Know thyself' is impossible and ridiculous [Nietzsche]
18. Thought / A. Modes of Thought / 1. Thought
Thoughts cannot be fully reproduced in words [Nietzsche]
18. Thought / A. Modes of Thought / 5. Rationality / a. Rationality
Most of our intellectual activity is unconscious [Nietzsche]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / c. Ethical intuitionism
Why do you listen to the voice of your conscience? [Nietzsche]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / f. Übermensch
Higher human beings see and hear far more than others, and do it more thoughtfully [Nietzsche]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / g. Will to power
A morality ranks human drives and actions, for the sake of the herd, and subordinating individuals [Nietzsche]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / j. Ethics by convention
Nietzsche thought it 'childish' to say morality isn't binding because it varies between cultures [Nietzsche, by Foot]
23. Ethics / C. Virtue Theory / 1. Virtue Theory / c. Particularism
No two actions are the same [Nietzsche]
23. Ethics / C. Virtue Theory / 1. Virtue Theory / d. Virtue theory critique
Many virtues are harmful traps, but that is why other people praise them [Nietzsche]
23. Ethics / C. Virtue Theory / 3. Virtues / f. Compassion
You cannot advocate joyful wisdom while rejecting pity, because the two are complementary [Scruton on Nietzsche]
23. Ethics / D. Deontological Ethics / 4. Categorical Imperative
To see one's own judgement as a universal law is selfish [Nietzsche]
23. Ethics / F. Existentialism / 1. Existentialism
We should give style to our character - by applying an artistic plan to its strengths and weaknesses [Nietzsche]
23. Ethics / F. Existentialism / 2. Nihilism
The ethical teacher exists to give purpose to what happens necessarily and without purpose [Nietzsche]
23. Ethics / F. Existentialism / 4. Boredom
To ward off boredom at any cost is vulgar [Nietzsche]
23. Ethics / F. Existentialism / 7. Existential Action
The best life is the dangerous life [Nietzsche]
23. Ethics / F. Existentialism / 8. Eternal Recurrence
Imagine if before each of your actions you had to accept repeating the action over and over again [Nietzsche]
Nietzsche says facing up to the eternal return of meaninglessness is the response to nihilism [Nietzsche, by Critchley]
28. God / C. Attitudes to God / 5. Atheism
God is dead, and we have killed him [Nietzsche]