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All the ideas for 'Mere Possibilities', 'Metaphysical Themes 1274-1671' and 'Philosophy of Mathematics'

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129 ideas

1. Philosophy / C. History of Philosophy / 1. History of Philosophy
Original philosophers invariably seek inspiration from past thinkers [Pasnau]
Philosophy consists of choosing between Plato, Aristotle and Democritus [Pasnau]
1. Philosophy / C. History of Philosophy / 3. Earlier European Philosophy / b. Early medieval philosophy
The commentaries of Averroes were the leading guide to Aristotle [Pasnau]
Modernity begins in the late 12th century, with Averroes's commentaries on Aristotle [Pasnau]
1. Philosophy / C. History of Philosophy / 3. Earlier European Philosophy / c. Later medieval philosophy
Once accidents were seen as real, 'Categories' became the major text for ontology [Pasnau]
In 1347, the Church effectively stopped philosophy for the next 300 years [Pasnau]
1. Philosophy / C. History of Philosophy / 3. Earlier European Philosophy / d. Renaissance philosophy
Renaissance Platonism is peripheral [Pasnau]
Plato only made an impact locally in 15th century Italy [Pasnau]
After c.1450 all of Plato was available. Before that, only the first half of 'Timaeus' was known [Pasnau]
1. Philosophy / C. History of Philosophy / 4. Later European Philosophy / b. Seventeenth century philosophy
Philosophy could easily have died in 17th century, if it weren't for Descartes [Pasnau]
The 17th century is a metaphysical train wreck [Pasnau]
1. Philosophy / E. Nature of Metaphysics / 1. Nature of Metaphysics
I don't think Lewis's cost-benefit reflective equilibrium approach offers enough guidance [Stalnaker]
2. Reason / B. Laws of Thought / 6. Ockham's Razor
Anti-Razor: if you can't account for a truth, keep positing things until you can [Pasnau]
2. Reason / D. Definition / 8. Impredicative Definition
Impredicative definitions are wrong, because they change the set that is being defined? [Bostock]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / a. Systems of modal logic
Non-S5 can talk of contingent or necessary necessities [Stalnaker]
4. Formal Logic / E. Nonclassical Logics / 2. Intuitionist Logic
Classical interdefinitions of logical constants and quantifiers is impossible in intuitionism [Bostock]
4. Formal Logic / F. Set Theory ST / 1. Set Theory
There is no single agreed structure for set theory [Bostock]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / a. Types of set
A 'proper class' cannot be a member of anything [Bostock]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
We could add axioms to make sets either as small or as large as possible [Bostock]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / b. Axiom of Extensionality I
In modal set theory, sets only exist in a possible world if that world contains all of its members [Stalnaker]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
The Axiom of Choice relies on reference to sets that we are unable to describe [Bostock]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / f. Limitation of Size
Replacement enforces a 'limitation of size' test for the existence of sets [Bostock]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
The completeness of first-order logic implies its compactness [Bostock]
First-order logic is not decidable: there is no test of whether any formula is valid [Bostock]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
We regiment to get semantic structure, for evaluating arguments, and understanding complexities [Stalnaker]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / e. or
In 'S was F or some other than S was F', the disjuncts need S, but the whole disjunction doesn't [Stalnaker]
5. Theory of Logic / G. Quantification / 4. Substitutional Quantification
Substitutional quantification is just standard if all objects in the domain have a name [Bostock]
5. Theory of Logic / H. Proof Systems / 4. Natural Deduction
The Deduction Theorem is what licenses a system of natural deduction [Bostock]
5. Theory of Logic / L. Paradox / 4. Paradoxes in Logic / c. Berry's paradox
Berry's Paradox considers the meaning of 'The least number not named by this name' [Bostock]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / b. Types of number
ω + 1 is a new ordinal, but its cardinality is unchanged [Bostock]
Each addition changes the ordinality but not the cardinality, prior to aleph-1 [Bostock]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / c. Priority of numbers
A cardinal is the earliest ordinal that has that number of predecessors [Bostock]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / f. Cardinal numbers
Aleph-1 is the first ordinal that exceeds aleph-0 [Bostock]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
Instead of by cuts or series convergence, real numbers could be defined by axioms [Bostock]
The number of reals is the number of subsets of the natural numbers [Bostock]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / i. Reals from cuts
For Eudoxus cuts in rationals are unique, but not every cut makes a real number [Bostock]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / k. Infinitesimals
Infinitesimals are not actually contradictory, because they can be non-standard real numbers [Bostock]
6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry
Modern axioms of geometry do not need the real numbers [Bostock]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / d. Peano arithmetic
The Peano Axioms describe a unique structure [Bostock]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / d. Hume's Principle
There are many criteria for the identity of numbers [Bostock]
Hume's Principle is a definition with existential claims, and won't explain numbers [Bostock]
Many things will satisfy Hume's Principle, so there are many interpretations of it [Bostock]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / e. Caesar problem
Frege makes numbers sets to solve the Caesar problem, but maybe Caesar is a set! [Bostock]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / e. Structuralism critique
Numbers can't be positions, if nothing decides what position a given number has [Bostock]
Structuralism falsely assumes relations to other numbers are numbers' only properties [Bostock]
6. Mathematics / C. Sources of Mathematics / 3. Mathematical Nominalism
Nominalism about mathematics is either reductionist, or fictionalist [Bostock]
Nominalism as based on application of numbers is no good, because there are too many applications [Bostock]
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / b. Indispensability of mathematics
Actual measurement could never require the precision of the real numbers [Bostock]
6. Mathematics / C. Sources of Mathematics / 5. Numbers as Adjectival
Ordinals are mainly used adjectively, as in 'the first', 'the second'... [Bostock]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / b. Type theory
Simple type theory has 'levels', but ramified type theory has 'orders' [Bostock]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / c. Neo-logicism
Neo-logicists agree that HP introduces number, but also claim that it suffices for the job [Bostock]
Neo-logicists meet the Caesar problem by saying Hume's Principle is unique to number [Bostock]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
Treating numbers as objects doesn't seem like logic, since arithmetic fixes their totality [Bostock]
Many crucial logicist definitions are in fact impredicative [Bostock]
If Hume's Principle is the whole story, that implies structuralism [Bostock]
6. Mathematics / C. Sources of Mathematics / 9. Fictional Mathematics
Higher cardinalities in sets are just fairy stories [Bostock]
A fairy tale may give predictions, but only a true theory can give explanations [Bostock]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / c. Conceptualism
The best version of conceptualism is predicativism [Bostock]
Conceptualism fails to grasp mathematical properties, infinity, and objective truth values [Bostock]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / d. Predicativism
The usual definitions of identity and of natural numbers are impredicative [Bostock]
If abstracta only exist if they are expressible, there can only be denumerably many of them [Bostock]
Predicativism makes theories of huge cardinals impossible [Bostock]
If mathematics rests on science, predicativism may be the best approach [Bostock]
If we can only think of what we can describe, predicativism may be implied [Bostock]
The predicativity restriction makes a difference with the real numbers [Bostock]
7. Existence / A. Nature of Existence / 1. Nature of Existence
Some say what exists must do so, and nothing else could possible exist [Stalnaker]
A nominalist view says existence is having spatio-temporal location [Stalnaker]
7. Existence / C. Structure of Existence / 1. Grounding / a. Nature of grounding
Priority was a major topic of dispute for scholastics [Pasnau]
7. Existence / C. Structure of Existence / 8. Stuff / b. Mixtures
In mixtures, the four elements ceased to exist, replaced by a mixed body with a form [Pasnau]
8. Modes of Existence / B. Properties / 1. Nature of Properties
Properties are modal, involving possible situations where they are exemplified [Stalnaker]
8. Modes of Existence / B. Properties / 3. Types of Properties
17th C qualities are either microphysical, or phenomenal, or powers [Pasnau]
8. Modes of Existence / B. Properties / 6. Categorical Properties
17th century authors only recognised categorical properties, never dispositions [Pasnau]
8. Modes of Existence / B. Properties / 8. Properties as Modes
The biggest question for scholastics is whether properties are real, or modes of substances [Pasnau]
8. Modes of Existence / B. Properties / 10. Properties as Predicates
I accept a hierarchy of properties of properties of properties [Stalnaker]
8. Modes of Existence / C. Powers and Dispositions / 4. Powers as Essence
There is no centralised power, but we still need essence for a metaphysical understanding [Pasnau]
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / a. Dispositions
Dispositions have modal properties, of which properties things would have counterfactually [Stalnaker]
Instead of adding Aristotelian forms to physical stuff, one could add dispositions [Pasnau]
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / b. Dispositions and powers
Scholastics reject dispositions, because they are not actual, as forms require [Pasnau]
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
Scholastics say there is a genuine thing if it is 'separable' [Pasnau]
9. Objects / A. Existence of Objects / 5. Individuation / b. Individuation by properties
If you reject essences, questions of individuation become extremely difficult [Pasnau]
Scholastics thought Quantity could be the principle of individuation [Pasnau]
9. Objects / B. Unity of Objects / 2. Substance / a. Substance
Corpuscularian critics of scholasticism say only substances exist [Pasnau]
Corpuscularianism promised a decent account of substance [Pasnau]
Scholastics wanted to treat Aristotelianism as physics, rather than as metaphysics [Pasnau]
If crowds are things at all, they seem to be Substances, since they bear properties [Pasnau]
9. Objects / B. Unity of Objects / 2. Substance / c. Types of substance
Scholastics use 'substantia' for thick concrete entities, and for thin metaphysical ones [Pasnau]
9. Objects / B. Unity of Objects / 2. Substance / e. Substance critique
For corpuscularians, a substance is just its integral parts [Pasnau]
9. Objects / B. Unity of Objects / 3. Unity Problems / c. Statue and clay
If clay survives destruction of the statue, the statue wasn't a substance, but a mere accident [Pasnau]
9. Objects / C. Structure of Objects / 2. Hylomorphism / a. Hylomorphism
Corpuscularianism rejected not only form, but also the dependence of matter on form [Pasnau]
9. Objects / C. Structure of Objects / 2. Hylomorphism / b. Form as principle
Hylomorphism may not be a rival to science, but an abstract account of unity and endurance [Pasnau]
9. Objects / C. Structure of Objects / 2. Hylomorphism / c. Form as causal
Hylomorphism declined because scholastics made it into a testable physical theory [Pasnau]
Scholastics made forms substantial, in a way unintended by Aristotle [Pasnau]
Scholastics began to see substantial form more as Aristotle's 'efficient' cause [Pasnau]
9. Objects / C. Structure of Objects / 2. Hylomorphism / d. Form as unifier
Aquinas says a substance has one form; Scotists say it has many forms [Pasnau]
9. Objects / C. Structure of Objects / 4. Quantity of an Object
Scholastic Quantity either gives a body parts, or spreads them out in a unified way [Pasnau]
9. Objects / C. Structure of Objects / 7. Substratum
A substrate may be 'prime matter', which endures through every change [Pasnau]
There may be different types of substrate, or temporary substrates [Pasnau]
If a substrate gives causal support for change, quite a lot of the ingredients must endure [Pasnau]
A substratum can't be 'bare', because it has a job to do [Pasnau]
9. Objects / D. Essence of Objects / 7. Essence and Necessity / a. Essence as necessary properties
'Socrates is essentially human' seems to say nothing could be Socrates if it was not human [Stalnaker]
9. Objects / D. Essence of Objects / 7. Essence and Necessity / b. Essence not necessities
Aristotelians deny that all necessary properties are essential [Pasnau]
9. Objects / E. Objects over Time / 6. Successive Things
Typical successive things are time and motion [Pasnau]
9. Objects / E. Objects over Time / 10. Beginning of an Object
Weak ex nihilo says it all comes from something; strong version says the old must partly endure [Pasnau]
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
The bundle theory makes the identity of indiscernibles a necessity, since the thing is the properties [Stalnaker]
10. Modality / A. Necessity / 3. Types of Necessity
Strong necessity is always true; weak necessity is cannot be false [Stalnaker]
10. Modality / C. Sources of Modality / 2. Necessity as Primitive
Necessity and possibility are fundamental, and there can be no reductive analysis of them [Stalnaker]
10. Modality / C. Sources of Modality / 5. Modality from Actuality
Modal concepts are central to the actual world, and shouldn't need extravagant metaphysics [Stalnaker]
10. Modality / E. Possible worlds / 1. Possible Worlds / d. Possible worlds actualism
Given actualism, how can there be possible individuals, other than the actual ones? [Stalnaker]
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / a. Nature of possible worlds
Possible worlds are properties [Stalnaker]
Possible worlds don't reduce modality, they regiment it to reveal its structure [Stalnaker]
I think of worlds as cells (rather than points) in logical space [Stalnaker]
10. Modality / E. Possible worlds / 3. Transworld Objects / c. Counterparts
Modal properties depend on the choice of a counterpart, which is unconstrained by metaphysics [Stalnaker]
10. Modality / E. Possible worlds / 3. Transworld Objects / d. Haecceitism
Anti-haecceitism says there is no more to an individual than meeting some qualitative conditions [Stalnaker]
14. Science / D. Explanation / 2. Types of Explanation / k. Explanations by essence
Essences must explain, so we can infer them causally from the accidents [Pasnau]
18. Thought / C. Content / 6. Broad Content
How can we know what we are thinking, if content depends on something we don't know? [Stalnaker]
19. Language / C. Assigning Meanings / 2. Semantics
We still lack an agreed semantics for quantifiers in natural language [Stalnaker]
19. Language / C. Assigning Meanings / 8. Possible Worlds Semantics
Possible world semantics may not reduce modality, but it can explain it [Stalnaker]
19. Language / D. Propositions / 1. Propositions
I take propositions to be truth conditions [Stalnaker]
A theory of propositions at least needs primitive properties of consistency and of truth [Stalnaker]
19. Language / D. Propositions / 3. Concrete Propositions
Propositions presumably don't exist if the things they refer to don't exist [Stalnaker]
19. Language / F. Communication / 2. Assertion
In logic a proposition means the same when it is and when it is not asserted [Bostock]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / g. Atomism
Atomists say causation is mechanical collisions, and all true qualities are microscopic [Pasnau]
26. Natural Theory / A. Speculations on Nature / 7. Later Matter Theories / a. Early Modern matter
In the 17th C matter became body, and was then studied by science [Pasnau]
26. Natural Theory / A. Speculations on Nature / 7. Later Matter Theories / b. Corpuscles
Atomism is the commonest version of corpuscularianism, but isn't required by it [Pasnau]
If there are just arrangements of corpuscles, where are the boundaries between substances? [Pasnau]
26. Natural Theory / C. Causation / 2. Types of cause
Scholastic causation is by changes in the primary qualities of hot, cold, wet, dry [Pasnau]
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / a. Scientific essentialism
Substantial forms were a step towards scientific essentialism [Pasnau]
27. Natural Reality / E. Cosmology / 3. The Beginning
Scholastic authors agree that matter was created by God, out of nothing [Pasnau]
29. Religion / B. Monotheistic Religion / 4. Christianity / b. Transubstantiation
Transubstantion says accidents of bread and wine don't inhere in the substance [Pasnau]