Combining Philosophers

All the ideas for Adolph Rami, John Mayberry and Dorothy Edgington

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80 ideas

2. Reason / D. Definition / 2. Aims of Definition
Definitions make our intuitions mathematically useful [Mayberry]
2. Reason / E. Argument / 6. Conclusive Proof
Proof shows that it is true, but also why it must be true [Mayberry]
3. Truth / B. Truthmakers / 1. For Truthmakers
There are five problems which the truth-maker theory might solve [Rami]
The truth-maker idea is usually justified by its explanatory power, or intuitive appeal [Rami]
3. Truth / B. Truthmakers / 2. Truthmaker Relation
The truth-making relation can be one-to-one, or many-to-many [Rami]
3. Truth / B. Truthmakers / 3. Truthmaker Maximalism
Central idea: truths need truthmakers; and possibly all truths have them, and makers entail truths [Rami]
3. Truth / B. Truthmakers / 4. Truthmaker Necessitarianism
Most theorists say that truth-makers necessitate their truths [Rami]
3. Truth / B. Truthmakers / 5. What Makes Truths / a. What makes truths
It seems best to assume different kinds of truth-maker, such as objects, facts, tropes, or events [Rami]
3. Truth / B. Truthmakers / 5. What Makes Truths / c. States of affairs make truths
Truth-makers seem to be states of affairs (plus optional individuals), or individuals and properties [Rami]
3. Truth / B. Truthmakers / 5. What Makes Truths / d. Being makes truths
'Truth supervenes on being' only gives necessary (not sufficient) conditions for contingent truths [Rami]
'Truth supervenes on being' avoids entities as truth-makers for negative truths [Rami]
3. Truth / B. Truthmakers / 7. Making Modal Truths
Maybe a truth-maker also works for the entailments of the given truth [Rami]
3. Truth / B. Truthmakers / 11. Truthmaking and Correspondence
Truth-making is usually internalist, but the correspondence theory is externalist [Rami]
3. Truth / C. Correspondence Truth / 1. Correspondence Truth
Correspondence theories assume that truth is a representation relation [Rami]
3. Truth / H. Deflationary Truth / 2. Deflationary Truth
Deflationist truth is an infinitely disjunctive property [Rami]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / c. Derivation rules of PL
Conditional Proof is only valid if we accept the truth-functional reading of 'if' [Edgington]
4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula
Truth-maker theorists should probably reject the converse Barcan formula [Rami]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
Set theory can't be axiomatic, because it is needed to express the very notion of axiomatisation [Mayberry]
There is a semi-categorical axiomatisation of set-theory [Mayberry]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / f. Axiom of Infinity V
The misnamed Axiom of Infinity says the natural numbers are finite in size [Mayberry]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / e. Iterative sets
The set hierarchy doesn't rely on the dubious notion of 'generating' them [Mayberry]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / f. Limitation of Size
Limitation of size is part of the very conception of a set [Mayberry]
5. Theory of Logic / A. Overview of Logic / 2. History of Logic
The mainstream of modern logic sees it as a branch of mathematics [Mayberry]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
First-order logic only has its main theorems because it is so weak [Mayberry]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Only second-order logic can capture mathematical structure up to isomorphism [Mayberry]
5. Theory of Logic / G. Quantification / 2. Domain of Quantification
Big logic has one fixed domain, but standard logic has a domain for each interpretation [Mayberry]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
No Löwenheim-Skolem logic can axiomatise real analysis [Mayberry]
5. Theory of Logic / K. Features of Logics / 1. Axiomatisation
'Classificatory' axioms aim at revealing similarity in morphology of structures [Mayberry]
Axiomatiation relies on isomorphic structures being essentially the same [Mayberry]
'Eliminatory' axioms get rid of traditional ideal and abstract objects [Mayberry]
5. Theory of Logic / K. Features of Logics / 6. Compactness
No logic which can axiomatise arithmetic can be compact or complete [Mayberry]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
Real numbers can be eliminated, by axiom systems for complete ordered fields [Mayberry]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / b. Quantity
Greek quantities were concrete, and ratio and proportion were their science [Mayberry]
Real numbers were invented, as objects, to simplify and generalise 'quantity' [Mayberry]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
Cantor's infinite is an absolute, of all the sets or all the ordinal numbers [Mayberry]
Cantor extended the finite (rather than 'taming the infinite') [Mayberry]
6. Mathematics / B. Foundations for Mathematics / 1. Foundations for Mathematics
If proof and definition are central, then mathematics needs and possesses foundations [Mayberry]
The ultimate principles and concepts of mathematics are presumed, or grasped directly [Mayberry]
Foundations need concepts, definition rules, premises, and proof rules [Mayberry]
Axiom theories can't give foundations for mathematics - that's using axioms to explain axioms [Mayberry]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / d. Peano arithmetic
1st-order PA is only interesting because of results which use 2nd-order PA [Mayberry]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / g. Incompleteness of Arithmetic
It is only 2nd-order isomorphism which suggested first-order PA completeness [Mayberry]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
Set theory is not just first-order ZF, because that is inadequate for mathematics [Mayberry]
We don't translate mathematics into set theory, because it comes embodied in that way [Mayberry]
Set theory is not just another axiomatised part of mathematics [Mayberry]
8. Modes of Existence / A. Relations / 2. Internal Relations
Internal relations depend either on the existence of the relata, or on their properties [Rami]
9. Objects / A. Existence of Objects / 2. Abstract Objects / a. Nature of abstracta
Real numbers as abstracted objects are now treated as complete ordered fields [Mayberry]
9. Objects / C. Structure of Objects / 2. Hylomorphism / a. Hylomorphism
The extremes of essentialism are that all properties are essential, or only very trivial ones [Rami]
9. Objects / D. Essence of Objects / 3. Individual Essences
An 'individual essence' is possessed uniquely by a particular object [Rami]
9. Objects / D. Essence of Objects / 5. Essence as Kind
'Sortal essentialism' says being a particular kind is what is essential [Rami]
9. Objects / D. Essence of Objects / 7. Essence and Necessity / b. Essence not necessities
Unlosable properties are not the same as essential properties [Rami]
10. Modality / A. Necessity / 1. Types of Modality
There are two families of modal notions, metaphysical and epistemic, of equal strength [Edgington]
10. Modality / A. Necessity / 3. Types of Necessity
Physical possibility is part of metaphysical possibility which is part of logical possibility [Rami]
10. Modality / A. Necessity / 5. Metaphysical Necessity
Metaphysical possibility is discovered empirically, and is contrained by nature [Edgington]
10. Modality / A. Necessity / 6. Logical Necessity
Broadly logical necessity (i.e. not necessarily formal logical necessity) is an epistemic notion [Edgington]
Logical necessity is epistemic necessity, which is the old notion of a priori [Edgington, by McFetridge]
An argument is only valid if it is epistemically (a priori) necessary [Edgington]
10. Modality / B. Possibility / 2. Epistemic possibility
If it is possible 'for all I know' then it is 'epistemically possible' [Rami]
10. Modality / B. Possibility / 6. Probability
Truth-functional possibilities include the irrelevant, which is a mistake [Edgington]
A thing works like formal probability if all the options sum to 100% [Edgington]
Conclusion improbability can't exceed summed premise improbability in valid arguments [Edgington]
10. Modality / B. Possibility / 8. Conditionals / a. Conditionals
Validity can preserve certainty in mathematics, but conditionals about contingents are another matter [Edgington]
It is a mistake to think that conditionals are statements about how the world is [Edgington]
10. Modality / B. Possibility / 8. Conditionals / b. Types of conditional
Simple indicatives about past, present or future do seem to form a single semantic kind [Edgington]
Maybe forward-looking indicatives are best classed with the subjunctives [Edgington]
There are many different conditional mental states, and different conditional speech acts [Edgington]
10. Modality / B. Possibility / 8. Conditionals / c. Truth-function conditionals
Truth-function problems don't show up in mathematics [Edgington]
Are conditionals truth-functional - do the truth values of A and B determine the truth value of 'If A, B'? [Edgington]
'If A,B' must entail ¬(A & ¬B); otherwise we could have A true, B false, and If A,B true, invalidating modus ponens [Edgington]
Inferring conditionals from disjunctions or negated conjunctions gives support to truth-functionalism [Edgington]
The truth-functional view makes conditionals with unlikely antecedents likely to be true [Edgington]
Doctor:'If patient still alive, change dressing'; Nurse:'Either dead patient, or change dressing'; kills patient! [Edgington]
10. Modality / B. Possibility / 8. Conditionals / d. Non-truthfunction conditionals
A conditional does not have truth conditions [Edgington]
X believes 'if A, B' to the extent that A & B is more likely than A & ¬B [Edgington]
Non-truth-functionalist say 'If A,B' is false if A is T and B is F, but deny that is always true for TT,FT and FF [Edgington]
I say "If you touch that wire you'll get a shock"; you don't touch it. How can that make the conditional true? [Edgington]
10. Modality / B. Possibility / 8. Conditionals / e. Supposition conditionals
Conditionals express what would be the outcome, given some supposition [Edgington]
On the supposition view, believe if A,B to the extent that A&B is nearly as likely as A [Edgington]
10. Modality / B. Possibility / 8. Conditionals / f. Pragmatics of conditionals
Truth-functionalists support some conditionals which we assert, but should not actually believe [Edgington]
Does 'If A,B' say something different in each context, because of the possibiites there? [Edgington]