Combining Texts

All the ideas for 'Must We Believe in Set Theory?', 'Essays on Intellectual Powers 5: Abstraction' and 'Trees, Terms and Truth'

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


30 ideas

3. Truth / B. Truthmakers / 5. What Makes Truths / a. What makes truths
If facts are the truthmakers, they are not in the world [Engelbretsen]
There are no 'falsifying' facts, only an absence of truthmakers [Engelbretsen]
4. Formal Logic / A. Syllogistic Logic / 1. Aristotelian Logic
Traditional term logic struggled to express relations [Engelbretsen]
4. Formal Logic / A. Syllogistic Logic / 3. Term Logic
Term logic rests on negated terms or denial, and that propositions are tied pairs [Engelbretsen]
4. Formal Logic / F. Set Theory ST / 1. Set Theory
The logic of ZF is classical first-order predicate logic with identity [Boolos]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
A few axioms of set theory 'force themselves on us', but most of them don't [Boolos]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / d. Naïve logical sets
Naïve sets are inconsistent: there is no set for things that do not belong to themselves [Boolos]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / e. Iterative sets
The iterative conception says sets are formed at stages; some are 'earlier', and must be formed first [Boolos]
5. Theory of Logic / A. Overview of Logic / 2. History of Logic
Was logic a branch of mathematics, or mathematics a branch of logic? [Engelbretsen]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
Logical syntax is actually close to surface linguistic form [Engelbretsen]
Propositions can be analysed as pairs of terms glued together by predication [Engelbretsen]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / c. not
Standard logic only negates sentences, even via negated general terms or predicates [Engelbretsen]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
Infinite natural numbers is as obvious as infinite sentences in English [Boolos]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / f. Uncountable infinities
Mathematics and science do not require very high orders of infinity [Boolos]
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / a. For mathematical platonism
Mathematics isn't surprising, given that we experience many objects as abstract [Boolos]
7. Existence / A. Nature of Existence / 6. Criterion for Existence
Existence and nonexistence are characteristics of the world, not of objects [Engelbretsen]
7. Existence / D. Theories of Reality / 8. Facts / a. Facts
Facts are not in the world - they are properties of the world [Engelbretsen]
7. Existence / E. Categories / 4. Category Realism
Individuals are arranged in inclusion categories that match our semantics [Engelbretsen]
8. Modes of Existence / D. Universals / 1. Universals
It is lunacy to think we only see ink-marks, and not word-types [Boolos]
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 / A. Existence of Objects / 2. Abstract Objects / a. Nature of abstracta
I am a fan of abstract objects, and confident of their existence [Boolos]
9. Objects / A. Existence of Objects / 2. Abstract Objects / c. Modern abstracta
We deal with abstract objects all the time: software, poems, mistakes, triangles.. [Boolos]
9. Objects / F. Identity among Objects / 1. Concept of Identity
Real identity admits of no degrees [Reid]
18. Thought / A. Modes of Thought / 1. Thought
We must first conceive things before we can consider them [Reid]
18. Thought / E. Abstraction / 1. Abstract Thought
First we notice and name attributes ('abstracting'); then we notice that subjects share them ('generalising') [Reid]
19. Language / B. Reference / 2. Denoting
Terms denote objects with properties, and statements denote the world with that property [Engelbretsen]
19. Language / D. Propositions / 1. Propositions
'Socrates is wise' denotes a sentence; 'that Socrates is wise' denotes a proposition [Engelbretsen]
19. Language / F. Communication / 3. Denial
Negating a predicate term and denying its unnegated version are quite different [Engelbretsen]