Combining Philosophers

All the ideas for Penelope Maddy, Thomas Reid and Juan Comesaa

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132 ideas

1. Philosophy / F. Analytic Philosophy / 5. Linguistic Analysis
The existence of tensed verbs shows that not all truths are necessary truths [Reid]
2. Reason / F. Fallacies / 7. Ad Hominem
An ad hominem argument is good, if it is shown that the man's principles are inconsistent [Reid]
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 / 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]
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 / A. Nature of Existence / 1. Nature of Existence
Accepting the existence of anything presupposes the notion of existence [Reid]
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
Powers are quite distinct and simple, and so cannot be defined [Reid]
Thinkers say that matter has intrinsic powers, but is also passive and acted upon [Reid]
8. Modes of Existence / C. Powers and Dispositions / 3. Powers as Derived
It is obvious that there could not be a power without a subject which possesses it [Reid]
8. Modes of Existence / D. Universals / 5. Universals as Concepts
Universals are not objects of sense and cannot be imagined - but can be conceived [Reid]
8. Modes of Existence / E. Nominalism / 1. Nominalism / b. Nominalism about universals
Only individuals exist [Reid]
8. Modes of Existence / E. Nominalism / 2. Resemblance Nominalism
No one thinks two sheets possess a single whiteness, but all agree they are both white [Reid]
9. Objects / D. Essence of Objects / 4. Essence as Definition
Objects have an essential constitution, producing its qualities, which we are too ignorant to define [Reid]
9. Objects / E. Objects over Time / 1. Objects over Time
Continuity is needed for existence, otherwise we would say a thing existed after it ceased to exist [Reid]
9. Objects / E. Objects over Time / 13. No Identity over Time
We treat slowly changing things as identical for the sake of economy in language [Reid]
9. Objects / F. Identity among Objects / 1. Concept of Identity
Identity is familiar to common sense, but very hard to define [Reid]
Identity can only be affirmed of things which have a continued existence [Reid]
Real identity admits of no degrees [Reid]
10. Modality / D. Knowledge of Modality / 4. Conceivable as Possible / b. Conceivable but impossible
Impossibilites are easily conceived in mathematics and geometry [Reid, by Molnar]
11. Knowledge Aims / B. Certain Knowledge / 4. The Cogito
If someone denies that he is thinking when he is conscious of it, we can only laugh [Reid]
11. Knowledge Aims / C. Knowing Reality / 1. Perceptual Realism / b. Direct realism
The existence of ideas is no more obvious than the existence of external objects [Reid]
11. Knowledge Aims / C. Knowing Reality / 4. Solipsism
We are only aware of other beings through our senses; without that, we are alone in the universe [Reid]
12. Knowledge Sources / A. A Priori Knowledge / 2. Self-Evidence
Truths are self-evident to sensible persons who understand them clearly without prejudice [Reid]
12. Knowledge Sources / B. Perception / 1. Perception
Sensation is not committed to any external object, but perception is [Reid]
12. Knowledge Sources / B. Perception / 2. Qualities in Perception / c. Primary qualities
Primary qualities are the object of mathematics [Reid]
12. Knowledge Sources / B. Perception / 2. Qualities in Perception / d. Secondary qualities
Secondary qualities conjure up, and are confused with, the sensations which produce them [Reid]
12. Knowledge Sources / B. Perception / 5. Interpretation
It is unclear whether a toothache is in the mind or in the tooth, but the word has a single meaning [Reid]
12. Knowledge Sources / E. Direct Knowledge / 1. Common Sense
Reid is seen as the main direct realist of the eighteenth century [Reid, by Robinson,H]
Many truths seem obvious, and point to universal agreement - which is what we find [Reid]
In obscure matters the few must lead the many, but the many usually lead in common sense [Reid]
12. Knowledge Sources / E. Direct Knowledge / 4. Memory
Without memory we could have no concept of duration [Reid]
We all trust our distinct memories (but not our distinct imaginings) [Reid]
The theory of ideas, popular with philosophers, means past existence has to be proved [Reid]
13. Knowledge Criteria / B. Internal Justification / 3. Evidentialism / a. Evidence
People dislike believing without evidence, and try to avoid it [Reid]
13. Knowledge Criteria / B. Internal Justification / 5. Coherentism / b. Pro-coherentism
If non-rational evidence reaches us, it is reason which then makes use of it [Reid]
13. Knowledge Criteria / C. External Justification / 3. Reliabilism / a. Reliable knowledge
Reliabilist knowledge is evidence based belief, with high conditional probability [Comesaņa]
13. Knowledge Criteria / C. External Justification / 3. Reliabilism / b. Anti-reliabilism
In a sceptical scenario belief formation is unreliable, so no beliefs at all are justified? [Comesaņa]
How do we decide which exact process is the one that needs to be reliable? [Comesaņa]
13. Knowledge Criteria / C. External Justification / 7. Testimony
We treat testimony with a natural trade off of belief and caution [Reid, by Fricker,M]
15. Nature of Minds / A. Nature of Mind / 5. Unity of Mind
A person is a unity, and doesn't come in degrees [Reid]
15. Nature of Minds / B. Features of Minds / 1. Consciousness / a. Consciousness
Consciousness is an indefinable and unique operation [Reid]
15. Nature of Minds / B. Features of Minds / 1. Consciousness / e. Cause of consciousness
Consciousness is the power of mind to know itself, and minds are grounded in powers [Reid]
15. Nature of Minds / C. Capacities of Minds / 6. Idealisation
Science idealises the earth's surface, the oceans, continuities, and liquids [Maddy]
16. Persons / A. Concept of a Person / 2. Persons as Responsible
Personal identity is the basis of all rights, obligations and responsibility [Reid]
16. Persons / A. Concept of a Person / 3. Persons as Reasoners
I can hardly care about rational consequence if it wasn't me conceiving the antecedent [Reid]
16. Persons / D. Continuity of the Self / 2. Mental Continuity / a. Memory is Self
The identity of a thief is only known by similarity, but memory gives certainty in our own case [Reid]
16. Persons / D. Continuity of the Self / 2. Mental Continuity / c. Inadequacy of mental continuity
Memory reveals my past identity - but so does testimony of other witnesses [Reid]
If consciousness is transferable 20 persons can be 1; forgetting implies 1 can be 20 [Reid]
Boy same as young man, young man same as old man, old man not boy, if forgotten! [Reid]
If a stolen horse is identified by similitude, its identity is not therefore merely similitude [Reid]
If consciousness is personal identity, it is continually changing [Reid]
16. Persons / D. Continuity of the Self / 7. Self and Thinking
Thoughts change continually, but the self doesn't [Reid]
16. Persons / F. Free Will / 2. Sources of Free Will
The first motion or effect cannot be produced necessarily, so the First Cause must be a free agent [Reid]
16. Persons / F. Free Will / 3. Constraints on the will
A willed action needs reasonable understanding of what is to be done [Reid]
16. Persons / F. Free Will / 4. For Free Will
Our own nature attributes free determinations to our own will [Reid]
We are morally free, because we experience it, we are accountable, and we pursue projects [Reid]
18. Thought / A. Modes of Thought / 1. Thought
We must first conceive things before we can consider them [Reid]
18. Thought / A. Modes of Thought / 8. Human Thought
The structure of languages reveals a uniformity in basic human opinions [Reid]
18. Thought / C. Content / 2. Ideas
Only philosophers treat ideas as objects [Reid]
18. Thought / E. Abstraction / 1. Abstract Thought
First we notice and name attributes ('abstracting'); then we notice that subjects share them ('generalising') [Reid]
18. Thought / E. Abstraction / 2. Abstracta by Selection
If you can't distinguish the features of a complex object, your notion of it would be a muddle [Reid]
Only mature minds can distinguish the qualities of a body [Reid]
19. Language / A. Nature of Meaning / 9. Ambiguity
The ambiguity of words impedes the advancement of knowledge [Reid]
19. Language / B. Reference / 1. Reference theories
Reference is by name, or a term-plus-circumstance, or ostensively, or by description [Reid]
19. Language / B. Reference / 3. Direct Reference / c. Social reference
A word's meaning is the thing conceived, as fixed by linguistic experts [Reid]
20. Action / B. Preliminaries of Action / 2. Willed Action / c. Agent causation
Reid said that agent causation is a unique type of causation [Reid, by Stout,R]
20. Action / C. Motives for Action / 3. Acting on Reason / a. Practical reason
A motive is merely an idea, like advice, and not a force for action [Reid]
21. Aesthetics / A. Aesthetic Experience / 3. Taste
There are axioms of taste - such as a general consensus about a beautiful face [Reid]
22. Metaethics / C. The Good / 1. Goodness / g. Consequentialism
If an attempted poisoning results in benefits, we still judge the agent a poisoner [Reid]
23. Ethics / B. Contract Ethics / 2. Golden Rule
We shouldn't do to others what would be a wrong to us in similar circumstances [Reid]
23. Ethics / C. Virtue Theory / 1. Virtue Theory / b. Basis of virtue
To be virtuous, we must care about duty [Reid]
23. Ethics / C. Virtue Theory / 3. Virtues / e. Honour
Every worthy man has a principle of honour, and knows what is honourable [Reid]
26. Natural Theory / C. Causation / 1. Causation
Similar effects come from similar causes, and causes are only what are sufficient for the effects [Reid]
26. Natural Theory / C. Causation / 9. General Causation / a. Constant conjunction
Day and night are constantly conjoined, but they don't cause one another [Reid, by Crane]
We all know that mere priority or constant conjunction do not have to imply causation [Reid]
26. Natural Theory / C. Causation / 9. General Causation / d. Causal necessity
Regular events don't imply a cause, without an innate conviction of universal causation [Reid]
26. Natural Theory / D. Laws of Nature / 1. Laws of Nature
The principle of the law of nature is that matter is passive, and is acted upon [Reid]
Scientists don't know the cause of magnetism, and only discover its regulations [Reid]
Laws are rules for effects, but these need a cause; rules of navigation don't navigate [Reid]