Combining Philosophers

All the ideas for Porphyry, Carneades and Penelope Maddy

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89 ideas

1. Philosophy / D. Nature of Philosophy / 3. Philosophy Defined
Carneades' pinnacles of philosophy are the basis of knowledge (the criterion of truth) and the end of appetite (good) [Carneades, by Cicero]
1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / b. Philosophy as transcendent
Philosophy has its own mode of death, by separating soul from body [Porphyry]
3. Truth / B. Truthmakers / 10. Making Future Truths
Future events are true if one day we will say 'this event is happening now' [Carneades]
We say future things are true that will possess actuality at some following time [Carneades, by Cicero]
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
Extensional sets are clearer, simpler, unique and expressive [Maddy]
The Axiom of Extensionality seems to be analytic [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 / 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
Cantor and Dedekind brought completed infinities into mathematics [Maddy]
Completed infinities resulted from giving foundations to calculus [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
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]
Infinity has degrees, and large cardinals are the heart of set theory [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
Mathematics rests on the logic of proofs, and on the set theoretic axioms [Maddy]
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]
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]
Making set theory foundational to mathematics leads to very fruitful axioms [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]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / b. Mathematics is not set theory
Sets exist where their elements are, but numbers are more like universals [Maddy]
Number theory doesn't 'reduce' to set theory, because sets have number properties [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]
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]
8. Modes of Existence / C. Powers and Dispositions / 2. Powers as Basic
The presence of the incorporeal is only known by certain kinds of disposition [Porphyry]
8. Modes of Existence / D. Universals / 1. Universals
Are genera and species real or conceptual? bodies or incorporeal? in sensibles or separate from them? [Porphyry]
9. Objects / B. Unity of Objects / 1. Unifying an Object / a. Intrinsic unification
Diversity arises from the power of unity [Porphyry]
9. Objects / F. Identity among Objects / 6. Identity between Objects
Carneades denied the transitivity of identity [Carneades, by Chisholm]
10. Modality / A. Necessity / 3. Types of Necessity
Carneades distinguished logical from causal necessity, when talking of future events [Long on Carneades]
12. Knowledge Sources / E. Direct Knowledge / 4. Memory
Memory is not conserved images, but reproduction of previous thought [Porphyry]
15. Nature of Minds / A. Nature of Mind / 1. Mind / c. Features of mind
Intelligence is aware of itself, so the intelligence is both the thinker and the thought [Porphyry]
15. Nature of Minds / A. Nature of Mind / 1. Mind / d. Location of mind
The soul is everywhere and nowhere in the body, and must be its cause [Porphyry]
15. Nature of Minds / C. Capacities of Minds / 6. Idealisation
Science idealises the earth's surface, the oceans, continuities, and liquids [Maddy]
16. Persons / C. Self-Awareness / 2. Knowing the Self
Successful introspection reveals the substrate along with the object of thought [Porphyry]
16. Persons / F. Free Will / 2. Sources of Free Will
Voluntary motion is intrinsically within our power, and this power is its cause [Carneades, by Cicero]
16. Persons / F. Free Will / 6. Determinism / a. Determinism
Some actions are within our power; determinism needs prior causes for everything - so it is false [Carneades, by Cicero]
16. Persons / F. Free Will / 6. Determinism / b. Fate
Even Apollo can only foretell the future when it is naturally necessary [Carneades, by Cicero]
17. Mind and Body / A. Mind-Body Dualism / 1. Dualism
The soul is bound to matter by the force of its own disposition [Porphyry]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / e. Human nature
Justice is each person fulfilling his function [Porphyry]
22. Metaethics / B. Value / 2. Values / g. Love
We should avoid the pleasures of love, or at least, should not enact our dreams [Porphyry]
22. Metaethics / B. Value / 2. Values / i. Self-interest
Carneades said that after a shipwreck a wise man would seize the only plank by force [Carneades, by Tuck]
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / c. Motivation for virtue
Civil virtues make us behave benevolently, and thereby unite citizens [Porphyry]
Civil virtues control the passions, and make us conform to our nature [Porphyry]
Purificatory virtues detach the soul completely from the passions [Porphyry]
23. Ethics / C. Virtue Theory / 3. Virtues / a. Virtues
There are practical, purificatory, contemplative, and exemplary virtues [Porphyry]
25. Social Practice / D. Justice / 1. Basis of justice
People change laws for advantage; either there is no justice, or it is a form of self-injury [Carneades, by Lactantius]
26. Natural Theory / A. Speculations on Nature / 1. Nature
Unified real existence is neither great nor small, though greatness and smallness participate in it [Porphyry]
27. Natural Reality / D. Time / 1. Nature of Time / c. Idealist time
Time is the circular movement of the soul [Porphyry]
27. Natural Reality / D. Time / 1. Nature of Time / e. Eventless time
Some think time is seen at rest, as well as in movement [Porphyry]
28. God / A. Divine Nature / 2. Divine Nature
God is nowhere, and hence everywhere [Porphyry]
28. God / C. Attitudes to God / 2. Pantheism
Everything existing proceeds from divinity, and is within divinity [Porphyry]
29. Religion / D. Religious Issues / 2. Immortality / b. Soul
Nature binds or detaches body to soul, but soul itself joins and detaches soul from body [Porphyry]
Individual souls are all connected, though distinct, and without dividing universal Soul [Porphyry]