Combining Texts

All the ideas for 'Individuals without Sortals', 'Cantorian Abstraction: Recon. and Defence' and 'First-Order Logic'

expand these ideas     |    start again     |     specify just one area for these texts

28 ideas

5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
10282 Logic is the study of sound argument, or of certain artificial languages (or applying the latter to the former) [Hodges,W]
5. Theory of Logic / E. Structures of Logic / 4. Variables in Logic
9148 I think of variables as objects rather than as signs [Fine,K]
5. Theory of Logic / I. Semantics of Logic / 1. Semantics of Logic
10283 A formula needs an 'interpretation' of its constants, and a 'valuation' of its variables [Hodges,W]
10284 There are three different standard presentations of semantics [Hodges,W]
10285 I |= φ means that the formula φ is true in the interpretation I [Hodges,W]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
10288 Down Löwenheim-Skolem: if a countable language has a consistent theory, that has a countable model [Hodges,W]
10289 Up Löwenheim-Skolem: if infinite models, then arbitrarily large models [Hodges,W]
5. Theory of Logic / K. Features of Logics / 6. Compactness
10287 If a first-order theory entails a sentence, there is a finite subset of the theory which entails it [Hodges,W]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / d. Counting via concepts
17518 Counting 'coin in this box' may have coin as the unit, with 'in this box' merely as the scope [Ayers]
17516 If counting needs a sortal, what of things which fall under two sortals? [Ayers]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
10286 A 'set' is a mathematically well-behaved class [Hodges,W]
7. Existence / B. Change in Existence / 4. Events / a. Nature of events
17520 Events do not have natural boundaries, and we have to set them [Ayers]
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
17519 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
17510 Speakers need the very general category of a thing, if they are to think about it [Ayers]
17522 We use sortals to classify physical objects by the nature and origin of their unity [Ayers]
17515 Seeing caterpillar and moth as the same needs continuity, not identity of sortal concepts [Ayers]
17511 Recognising continuity is separate from sortals, and must precede their use [Ayers]
9. Objects / B. Unity of Objects / 1. Unifying an Object / a. Intrinsic unification
17517 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
17513 If there are two objects, then 'that marble, man-shaped object' is ambiguous [Ayers]
9. Objects / D. Essence of Objects / 5. Essence as Kind
17523 Sortals basically apply to individuals [Ayers]
9. Objects / E. Objects over Time / 5. Temporal Parts
17521 You can't have the concept of a 'stage' if you lack the concept of an object [Ayers]
17514 Temporal 'parts' cannot be separated or rearranged [Ayers]
9. Objects / F. Identity among Objects / 1. Concept of Identity
17509 Some say a 'covering concept' completes identity; others place the concept in the reference [Ayers]
9. Objects / F. Identity among Objects / 3. Relative Identity
17512 If diachronic identities need covering concepts, why not synchronic identities too? [Ayers]
15. Nature of Minds / C. Capacities of Minds / 5. Generalisation by mind
9152 If green is abstracted from a thing, it is only seen as a type if it is common to many things [Fine,K]
18. Thought / E. Abstraction / 2. Abstracta by Selection
9149 To obtain the number 2 by abstraction, we only want to abstract the distinctness of a pair of objects [Fine,K]
9150 We should define abstraction in general, with number abstraction taken as a special case [Fine,K]
18. Thought / E. Abstraction / 8. Abstractionism Critique
9146 After abstraction all numbers seem identical, so only 0 and 1 will exist! [Fine,K]