Combining Philosophers

All the ideas for Speussipus, Georges Rey and Penelope Maddy

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128 ideas

4. Formal Logic / F. Set Theory ST / 2. Mechanics of Set Theory / b. Terminology of ST
'Forcing' can produce new models of ZFC from old models [Maddy]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
A Large Cardinal Axiom would assert ever-increasing stages in the hierarchy [Maddy]
New axioms are being sought, to determine the size of the continuum [Maddy]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / b. Axiom of Extensionality I
The Axiom of Extensionality seems to be analytic [Maddy]
Extensional sets are clearer, simpler, unique and expressive [Maddy]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / f. Axiom of Infinity V
The Axiom of Infinity states Cantor's breakthrough that launched modern mathematics [Maddy]
Infinite sets are essential for giving an account of the real numbers [Maddy]
Axiom of Infinity: completed infinite collections can be treated mathematically [Maddy]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / g. Axiom of Powers VI
The Power Set Axiom is needed for, and supported by, accounts of the continuum [Maddy]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / i. Axiom of Foundation VIII
The Axiom of Foundation says every set exists at a level in the set hierarchy [Maddy]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
Efforts to prove the Axiom of Choice have failed [Maddy]
Modern views say the Choice set exists, even if it can't be constructed [Maddy]
A large array of theorems depend on the Axiom of Choice [Maddy]
The Axiom of Choice paradoxically allows decomposing a sphere into two identical spheres [Maddy]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / p. Axiom of Reducibility
Axiom of Reducibility: propositional functions are extensionally predicative [Maddy]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / e. Iterative sets
The Iterative Conception says everything appears at a stage, derived from the preceding appearances [Maddy]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / f. Limitation of Size
Limitation of Size is a vague intuition that over-large sets may generate paradoxes [Maddy]
4. Formal Logic / F. Set Theory ST / 7. Natural Sets
The master science is physical objects divided into sets [Maddy]
Maddy replaces pure sets with just objects and perceived sets of objects [Maddy, by Shapiro]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Henkin semantics is more plausible for plural logic than for second-order logic [Maddy]
5. Theory of Logic / C. Ontology of Logic / 3. If-Thenism
Critics of if-thenism say that not all starting points, even consistent ones, are worth studying [Maddy]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
'Propositional functions' are propositions with a variable as subject or predicate [Maddy]
5. Theory of Logic / F. Referring in Logic / 1. Naming / d. Singular terms
Varieties of singular terms are used to designate token particulars [Rey]
5. Theory of Logic / K. Features of Logics / 1. Axiomatisation
Hilbert's geometry and Dedekind's real numbers were role models for axiomatization [Maddy]
If two mathematical themes coincide, that suggest a single deep truth [Maddy]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / d. Actual infinite
Completed infinities resulted from giving foundations to calculus [Maddy]
Cantor and Dedekind brought completed infinities into mathematics [Maddy]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / g. Continuum Hypothesis
Every infinite set of reals is either countable or of the same size as the full set of reals [Maddy]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / i. Cardinal infinity
Infinity has degrees, and large cardinals are the heart of set theory [Maddy]
For any cardinal there is always a larger one (so there is no set of all sets) [Maddy]
An 'inaccessible' cardinal cannot be reached by union sets or power sets [Maddy]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / l. Limits
Theorems about limits could only be proved once the real numbers were understood [Maddy]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / c. Fregean numbers
The extension of concepts is not important to me [Maddy]
In the ZFC hierarchy it is impossible to form Frege's set of all three-element sets [Maddy]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / e. Caesar problem
Frege solves the Caesar problem by explicitly defining each number [Maddy]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
Set theory (unlike the Peano postulates) can explain why multiplication is commutative [Maddy]
Standardly, numbers are said to be sets, which is neat ontology and epistemology [Maddy]
Numbers are properties of sets, just as lengths are properties of physical objects [Maddy]
A natural number is a property of sets [Maddy, by Oliver]
Making set theory foundational to mathematics leads to very fruitful axioms [Maddy]
Unified set theory gives a final court of appeal for mathematics [Maddy]
Set theory brings mathematics into one arena, where interrelations become clearer [Maddy]
Identifying geometric points with real numbers revealed the power of set theory [Maddy]
The line of rationals has gaps, but set theory provided an ordered continuum [Maddy]
Set-theory tracks the contours of mathematical depth and fruitfulness [Maddy]
Mathematics rests on the logic of proofs, and on the set theoretic axioms [Maddy]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / b. Mathematics is not set theory
Number theory doesn't 'reduce' to set theory, because sets have number properties [Maddy]
Sets exist where their elements are, but numbers are more like universals [Maddy]
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / b. Against mathematical platonism
If mathematical objects exist, how can we know them, and which objects are they? [Maddy]
6. Mathematics / C. Sources of Mathematics / 2. Intuition of Mathematics
Intuition doesn't support much mathematics, and we should question its reliability [Maddy, by Shapiro]
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / a. Mathematical empiricism
We know mind-independent mathematical truths through sets, which rest on experience [Maddy, by Jenkins]
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / b. Indispensability of mathematics
Scientists posit as few entities as possible, but set theorist posit as many as possible [Maddy]
Physics requires the existence of properties, and also the abstract objects of arithmetic [Rey]
Maybe applications of continuum mathematics are all idealisations [Maddy]
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / c. Against mathematical empiricism
The connection of arithmetic to perception has been idealised away in modern infinitary mathematics [Maddy]
6. Mathematics / C. Sources of Mathematics / 5. Numbers as Adjectival
Number words are unusual as adjectives; we don't say 'is five', and numbers always come first [Maddy]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / c. Neo-logicism
We can get arithmetic directly from HP; Law V was used to get HP from the definition of number [Maddy]
7. Existence / D. Theories of Reality / 11. Ontological Commitment / e. Ontological commitment problems
The theoretical indispensability of atoms did not at first convince scientists that they were real [Maddy]
9. Objects / B. Unity of Objects / 2. Substance / c. Types of substance
Speusippus suggested underlying principles for every substance, and ended with a huge list [Speussipus, by Aristotle]
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
The Indiscernibility of Identicals is a truism; but the Identity of Indiscernibles depends on possible identical worlds [Rey]
12. Knowledge Sources / A. A Priori Knowledge / 1. Nature of the A Priori
The traditional a priori is justified without experience; post-Quine it became unrevisable by experience [Rey]
12. Knowledge Sources / D. Empiricism / 1. Empiricism
Empiricism says experience is both origin and justification of all knowledge [Rey]
13. Knowledge Criteria / C. External Justification / 9. Naturalised Epistemology
Animal learning is separate from their behaviour [Rey]
14. Science / D. Explanation / 3. Best Explanation / a. Best explanation
Abduction could have true data and a false conclusion, and may include data not originally mentioned [Rey]
14. Science / D. Explanation / 3. Best Explanation / b. Ultimate explanation
It's not at all clear that explanation needs to stop anywhere [Rey]
15. Nature of Minds / A. Nature of Mind / 1. Mind / e. Questions about mind
The three theories are reduction, dualism, eliminativism [Rey]
15. Nature of Minds / B. Features of Minds / 1. Consciousness / e. Cause of consciousness
Is consciousness 40Hz oscillations in layers 5 and 6 of the visual cortex? [Rey]
15. Nature of Minds / B. Features of Minds / 3. Privacy
Dualist privacy is seen as too deep for even telepathy to reach [Rey]
15. Nature of Minds / B. Features of Minds / 4. Intentionality / b. Intentionality theories
Intentional explanations are always circular [Rey]
15. Nature of Minds / B. Features of Minds / 5. Qualia / a. Nature of qualia
Arithmetic and unconscious attitudes have no qualia [Rey]
Why qualia, and why this particular quale? [Rey]
15. Nature of Minds / B. Features of Minds / 5. Qualia / b. Qualia and intentionality
If qualia have no function, their attachment to thoughts is accidental [Rey]
Are qualia a type of propositional attitude? [Rey]
15. Nature of Minds / B. Features of Minds / 5. Qualia / c. Explaining qualia
Are qualia irrelevant to explaining the mind? [Rey]
15. Nature of Minds / B. Features of Minds / 6. Inverted Qualia
If colour fits a cone mapping hue, brightness and saturation, rotating the cone could give spectrum inversion [Rey]
15. Nature of Minds / C. Capacities of Minds / 6. Idealisation
Science idealises the earth's surface, the oceans, continuities, and liquids [Maddy]
16. Persons / B. Nature of the Self / 6. Self as Higher Awareness
Self-consciousness may just be nested intentionality [Rey]
16. Persons / C. Self-Awareness / 4. Errors in Introspection
Experiments prove that people are often unaware of their motives [Rey]
Brain damage makes the unreliability of introspection obvious [Rey]
16. Persons / F. Free Will / 5. Against Free Will
If reason could be explained in computational terms, there would be no need for the concept of 'free will' [Rey]
Free will isn't evidence against a theory of thought if there is no evidence for free will [Rey]
17. Mind and Body / B. Behaviourism / 1. Behaviourism
Maybe behaviourists should define mental states as a group [Rey]
Behaviourism is eliminative, or reductionist, or methodological [Rey]
17. Mind and Body / B. Behaviourism / 4. Behaviourism Critique
Animals don't just respond to stimuli, they experiment [Rey]
How are stimuli and responses 'similar'? [Rey]
Behaviour is too contingent and irrelevant to be the mind [Rey]
17. Mind and Body / C. Functionalism / 1. Functionalism
If a normal person lacked a brain, would you say they had no mind? [Rey]
Dualism and physicalism explain nothing, and don't suggest any research [Rey]
17. Mind and Body / C. Functionalism / 6. Homuncular Functionalism
Homuncular functionalism (e.g. Freud) could be based on simpler mechanical processes [Rey]
17. Mind and Body / C. Functionalism / 7. Chinese Room
Is the room functionally the same as a Chinese speaker? [Rey]
Searle is guilty of the fallacy of division - attributing a property of the whole to a part [Rey]
17. Mind and Body / C. Functionalism / 8. Functionalism critique
One computer program could either play chess or fight a war [Rey]
17. Mind and Body / E. Mind as Physical / 3. Eliminativism
If you explain water as H2O, you have reduced water, but not eliminated it [Rey]
Human behaviour can show law-like regularity, which eliminativism can't explain [Rey]
17. Mind and Body / E. Mind as Physical / 4. Connectionism
Pattern recognition is puzzling for computation, but makes sense for connectionism [Rey]
Connectionism explains well speed of perception and 'graceful degradation' [Rey]
Connectionism explains irrationality (such as the Gamblers' Fallacy) quite well [Rey]
Connectionism assigns numbers to nodes and branches, and plots the outcomes [Rey]
17. Mind and Body / E. Mind as Physical / 7. Anti-Physicalism / a. Physicalism critique
Can identity explain reason, free will, non-extension, intentionality, subjectivity, experience? [Rey]
Physicalism offers something called "complexity" instead of mental substance [Rey]
18. Thought / A. Modes of Thought / 2. Propositional Attitudes
Some attitudes are information (belief), others motivate (hatred) [Rey]
18. Thought / B. Mechanics of Thought / 3. Modularity of Mind
Good grammar can't come simply from stimuli [Rey]
Children speak 90% good grammar [Rey]
18. Thought / B. Mechanics of Thought / 4. Language of Thought
Animals may also use a language of thought [Rey]
We train children in truth, not in grammar [Rey]
18. Thought / B. Mechanics of Thought / 6. Artificial Thought / a. Artificial Intelligence
Images can't replace computation, as they need it [Rey]
CRTT is good on deduction, but not so hot on induction, abduction and practical reason [Rey]
18. Thought / C. Content / 1. Content
Problem-solving clearly involves manipulating images [Rey]
Animals map things over time as well as over space [Rey]
18. Thought / C. Content / 6. Broad Content
Simple externalism is that the meaning just is the object [Rey]
18. Thought / D. Concepts / 4. Structure of Concepts / h. Family resemblance
Anything bears a family resemblance to a game, but obviously not anything counts as one [Rey]
19. Language / A. Nature of Meaning / 5. Meaning as Verification
A one hour gap in time might be indirectly verified, but then almost anything could be [Rey]
19. Language / A. Nature of Meaning / 6. Meaning as Use
The meaning of "and" may be its use, but not of "animal" [Rey]
19. Language / A. Nature of Meaning / 7. Meaning Holism / b. Language holism
Semantic holism means new evidence for a belief changes the belief, and we can't agree on concepts [Rey]
19. Language / A. Nature of Meaning / 8. Synonymy
Externalist synonymy is there being a correct link to the same external phenomena [Rey]
19. Language / B. Reference / 3. Direct Reference / b. Causal reference
Causal theories of reference (by 'dubbing') don't eliminate meanings in the heads of dubbers [Rey]
If meaning and reference are based on causation, then virtually everything has meaning [Rey]
19. Language / B. Reference / 4. Descriptive Reference / a. Sense and reference
Referential Opacity says truth is lost when you substitute one referring term ('mother') for another ('Jocasta') [Rey]
19. Language / E. Analyticity / 1. Analytic Propositions
'Married' does not 'contain' its symmetry, nor 'bigger than' its transitivity [Rey]
Analytic judgements can't be explained by contradiction, since that is what is assumed [Rey]
Analytic statements are undeniable (because of meaning), rather than unrevisable [Rey]
The meaning properties of a term are those which explain how the term is typically used [Rey]
An intrinsic language faculty may fix what is meaningful (as well as grammatical) [Rey]
Research throws doubts on the claimed intuitions which support analyticity [Rey]
19. Language / E. Analyticity / 4. Analytic/Synthetic Critique
If we claim direct insight to what is analytic, how do we know it is not sub-consciously empirical? [Rey]
19. Language / F. Communication / 5. Pragmatics / b. Implicature
A simple chaining device can't build sentences containing 'either..or', or 'if..then' [Rey]
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / h. Right feelings
Our desires become important when we have desires about desires [Rey]
28. God / C. Attitudes to God / 5. Atheism
Speusippus said things were governed by some animal force rather than the gods [Speussipus, by Cicero]