Combining Philosophers

All the ideas for M.R. Ayers, J. Alberto Coffa and Bernard Bolzano

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31 ideas

2. Reason / B. Laws of Thought / 1. Laws of Thought
The laws of thought are true, but they are not the axioms of logic [Bolzano, by George/Van Evra]
4. Formal Logic / F. Set Theory ST / 1. Set Theory
An aggregate in which order does not matter I call a 'set' [Bolzano]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
Choice suggests that intensions are not needed to ensure classes [Coffa]
6. Mathematics / A. Nature of Mathematics / 2. Geometry
Bolzano wanted to reduce all of geometry to arithmetic [Bolzano, by Brown,JR]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / d. Counting via concepts
Counting 'coin in this box' may have coin as the unit, with 'in this box' merely as the scope [Ayers]
If counting needs a sortal, what of things which fall under two sortals? [Ayers]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
A truly infinite quantity does not need to be a variable [Bolzano]
6. Mathematics / C. Sources of Mathematics / 2. Intuition of Mathematics
Bolzano began the elimination of intuition, by proving something which seemed obvious [Bolzano, by Dummett]
7. Existence / B. Change in Existence / 4. Events / a. Nature of events
Events do not have natural boundaries, and we have to set them [Ayers]
7. Existence / C. Structure of Existence / 1. Grounding / c. Grounding and explanation
Philosophical proofs in mathematics establish truths, and also show their grounds [Bolzano, by Correia/Schnieder]
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
To express borderline cases of objects, you need the concept of an 'object' [Ayers]
9. Objects / A. Existence of Objects / 5. Individuation / e. Individuation by kind
Recognising continuity is separate from sortals, and must precede their use [Ayers]
Speakers need the very general category of a thing, if they are to think about it [Ayers]
We use sortals to classify physical objects by the nature and origin of their unity [Ayers]
Seeing caterpillar and moth as the same needs continuity, not identity of sortal concepts [Ayers]
9. Objects / B. Unity of Objects / 1. Unifying an Object / a. Intrinsic unification
Could the same matter have more than one form or principle of unity? [Ayers]
9. Objects / B. Unity of Objects / 3. Unity Problems / c. Statue and clay
If there are two objects, then 'that marble, man-shaped object' is ambiguous [Ayers]
9. Objects / D. Essence of Objects / 5. Essence as Kind
Sortals basically apply to individuals [Ayers]
9. Objects / E. Objects over Time / 5. Temporal Parts
You can't have the concept of a 'stage' if you lack the concept of an object [Ayers]
Temporal 'parts' cannot be separated or rearranged [Ayers]
9. Objects / F. Identity among Objects / 1. Concept of Identity
Some say a 'covering concept' completes identity; others place the concept in the reference [Ayers]
9. Objects / F. Identity among Objects / 3. Relative Identity
If diachronic identities need covering concepts, why not synchronic identities too? [Ayers]
12. Knowledge Sources / A. A Priori Knowledge / 8. A Priori as Analytic
The semantic tradition aimed to explain the a priori semantically, not by Kantian intuition [Coffa]
12. Knowledge Sources / A. A Priori Knowledge / 11. Denying the A Priori
Platonism defines the a priori in a way that makes it unknowable [Coffa]
12. Knowledge Sources / E. Direct Knowledge / 2. Intuition
Bolzano wanted to avoid Kantian intuitions, and prove everything that could be proved [Bolzano, by Dummett]
15. Nature of Minds / C. Capacities of Minds / 5. Generalisation by mind
Mathematics generalises by using variables [Coffa]
19. Language / D. Propositions / 1. Propositions
Bolzano saw propositions as objective entities, existing independently of us [Bolzano, by Potter]
19. Language / D. Propositions / 2. Abstract Propositions / a. Propositions as sense
Propositions are abstract structures of concepts, ready for judgement or assertion [Bolzano, by Correia/Schnieder]
A 'proposition' is the sense of a linguistic expression, and can be true or false [Bolzano]
19. Language / E. Analyticity / 2. Analytic Truths
The ground of a pure conceptual truth is only in other conceptual truths [Bolzano]
27. Natural Reality / D. Time / 1. Nature of Time / a. Absolute time
Relativity is as absolutist about space-time as Newton was about space [Coffa]