Combining Texts

All the ideas for 'Theaetetus', 'Science without Numbers' and 'Alfred Tarski: life and logic'

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66 ideas

1. Philosophy / D. Nature of Philosophy / 7. Despair over Philosophy
Philosophers are always switching direction to something more interesting [Plato]
1. Philosophy / F. Analytic Philosophy / 2. Analysis by Division
Understanding mainly involves knowing the elements, not their combinations [Plato]
Either a syllable is its letters (making parts as knowable as whole) or it isn't (meaning it has no parts) [Plato]
2. Reason / A. Nature of Reason / 6. Coherence
A rational account is essentially a weaving together of things with names [Plato]
2. Reason / C. Styles of Reason / 3. Eristic
Eristic discussion is aggressive, but dialectic aims to help one's companions in discussion [Plato]
2. Reason / D. Definition / 4. Real Definition
A primary element has only a name, and no logos, but complexes have an account, by weaving the names [Plato]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
The Axiom of Choice is consistent with the other axioms of set theory [Feferman/Feferman]
Axiom of Choice: a set exists which chooses just one element each of any set of sets [Feferman/Feferman]
Platonist will accept the Axiom of Choice, but others want criteria of selection or definition [Feferman/Feferman]
The Trichotomy Principle is equivalent to the Axiom of Choice [Feferman/Feferman]
Cantor's theories needed the Axiom of Choice, but it has led to great controversy [Feferman/Feferman]
4. Formal Logic / F. Set Theory ST / 8. Critique of Set Theory
In Field's Platonist view, set theory is false because it asserts existence for non-existent things [Field,H, by Chihara]
5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence
Logical consequence is defined by the impossibility of P and ¬q [Field,H, by Shapiro]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A structure is a 'model' when the axioms are true. So which of the structures are models? [Feferman/Feferman]
Tarski and Vaught established the equivalence relations between first-order structures [Feferman/Feferman]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
Löwenheim-Skolem Theorem, and Gödel's completeness of first-order logic, the earliest model theory [Feferman/Feferman]
Löwenheim-Skolem says if the sentences are countable, so is the model [Feferman/Feferman]
5. Theory of Logic / K. Features of Logics / 4. Completeness
If a sentence holds in every model of a theory, then it is logically derivable from the theory [Feferman/Feferman]
5. Theory of Logic / K. Features of Logics / 7. Decidability
'Recursion theory' concerns what can be solved by computing machines [Feferman/Feferman]
Both Principia Mathematica and Peano Arithmetic are undecidable [Feferman/Feferman]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / a. Numbers
In Field's version of science, space-time points replace real numbers [Field,H, by Szabó]
6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry
'Metric' axioms uses functions, points and numbers; 'synthetic' axioms give facts about space [Field,H]
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / a. For mathematical platonism
We master arithmetic by knowing all the numbers in our soul [Plato]
The Indispensability Argument is the only serious ground for the existence of mathematical entities [Field,H]
6. Mathematics / C. Sources of Mathematics / 3. Mathematical Nominalism
Nominalists try to only refer to physical objects, or language, or mental constructions [Field,H]
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / b. Indispensability of mathematics
The application of mathematics only needs its possibility, not its truth [Field,H, by Shapiro]
Hilbert explains geometry, by non-numerical facts about space [Field,H]
Field needs a semantical notion of second-order consequence, and that needs sets [Brown,JR on Field,H]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
It seems impossible to explain the idea that the conclusion is contained in the premises [Field,H]
6. Mathematics / C. Sources of Mathematics / 9. Fictional Mathematics
Mathematics is only empirical as regards which theory is useful [Field,H]
Abstractions can form useful counterparts to concrete statements [Field,H]
Why regard standard mathematics as truths, rather than as interesting fictions? [Field,H]
7. Existence / B. Change in Existence / 1. Nature of Change
There seem to be two sorts of change: alteration and motion [Plato]
7. Existence / D. Theories of Reality / 11. Ontological Commitment / a. Ontological commitment
You can reduce ontological commitment by expanding the logic [Field,H]
8. Modes of Existence / B. Properties / 12. Denial of Properties
Field presumes properties can be eliminated from science [Field,H, by Szabó]
9. Objects / A. Existence of Objects / 2. Abstract Objects / d. Problems with abstracta
Abstract objects are only applicable to the world if they are impure, and connect to the physical [Field,H]
9. Objects / C. Structure of Objects / 8. Parts of Objects / a. Parts of objects
If a word has no parts and has a single identity, it turns out to be the same kind of thing as a letter [Plato]
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
A sum is that from which nothing is lacking, which is a whole [Plato]
The whole can't be the parts, because it would be all of the parts, which is the whole [Plato]
11. Knowledge Aims / A. Knowledge / 1. Knowledge
Things are only knowable if a rational account (logos) is possible [Plato]
11. Knowledge Aims / A. Knowledge / 2. Understanding
Expertise is knowledge of the whole by means of the parts [Plato]
11. Knowledge Aims / A. Knowledge / 4. Belief / c. Aim of beliefs
It is impossible to believe something which is held to be false [Plato]
11. Knowledge Aims / A. Knowledge / 4. Belief / d. Cause of beliefs
How can a belief exist if its object doesn't exist? [Plato]
12. Knowledge Sources / B. Perception / 1. Perception
Perception is infallible, suggesting that it is knowledge [Plato]
Our senses could have been separate, but they converge on one mind [Plato]
12. Knowledge Sources / C. Rationalism / 1. Rationalism
With what physical faculty do we perceive pairs of opposed abstract qualities? [Plato]
Thought must grasp being itself before truth becomes possible [Plato]
You might mistake eleven for twelve in your senses, but not in your mind [Plato]
13. Knowledge Criteria / A. Justification Problems / 1. Justification / b. Need for justification
An inadequate rational account would still not justify knowledge [Plato]
13. Knowledge Criteria / A. Justification Problems / 2. Justification Challenges / a. Agrippa's trilemma
Parts and wholes are either equally knowable or equally unknowable [Plato]
Without distinguishing marks, how do I know what my beliefs are about? [Plato]
13. Knowledge Criteria / A. Justification Problems / 3. Internal or External / a. Pro-internalism
A rational account might be seeing an image of one's belief, like a reflection in a mirror [Plato]
A rational account involves giving an image, or analysis, or giving a differentiating mark [Plato]
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / a. Foundationalism
Maybe primary elements can be named, but not receive a rational account [Plato]
13. Knowledge Criteria / B. Internal Justification / 5. Coherentism / b. Pro-coherentism
A rational account of a wagon would mean knowledge of its hundred parts [Plato]
13. Knowledge Criteria / D. Scepticism / 5. Dream Scepticism
What evidence can be brought to show whether we are dreaming or not? [Plato]
13. Knowledge Criteria / E. Relativism / 6. Relativism Critique
If you claim that all beliefs are true, that includes beliefs opposed to your own [Plato]
Clearly some people are superior to others when it comes to medicine [Plato]
How can a relativist form opinions about what will happen in the future? [Plato]
14. Science / D. Explanation / 2. Types of Explanation / a. Types of explanation
Beneath every extrinsic explanation there is an intrinsic explanation [Field,H]
18. Thought / E. Abstraction / 4. Abstracta by Example
'Abstract' is unclear, but numbers, functions and sets are clearly abstract [Field,H]
27. Natural Reality / B. Modern Physics / 2. Electrodynamics / b. Fields
In theories of fields, space-time points or regions are causal agents [Field,H]
27. Natural Reality / C. Space / 4. Substantival Space
Both philosophy and physics now make substantivalism more attractive [Field,H]
27. Natural Reality / C. Space / 5. Relational Space
Relational space is problematic if you take the idea of a field seriously [Field,H]
28. God / A. Divine Nature / 6. Divine Morality / c. God is the good
God must be the epitome of goodness, and we can only approach a divine state by being as good as possible [Plato]
29. Religion / D. Religious Issues / 3. Problem of Evil / a. Problem of Evil
There must always be some force of evil ranged against good [Plato]