Combining Texts

All the ideas for 'On the Question of Absolute Undecidability', 'Commentary on Euclid's 'Elements'' and 'Defining 'Intrinsic' (with Rae Langton)'

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


12 ideas

2. Reason / D. Definition / 1. Definitions
Interdefinition is useless by itself, but if we grasp one separately, we have them both [Lewis]
4. Formal Logic / F. Set Theory ST / 1. Set Theory
Mathematical set theory has many plausible stopping points, such as finitism, and predicativism [Koellner]
'Reflection principles' say the whole truth about sets can't be captured [Koellner]
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
We have no argument to show a statement is absolutely undecidable [Koellner]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / i. Cardinal infinity
There are at least eleven types of large cardinal, of increasing logical strength [Koellner]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / d. Peano arithmetic
PA is consistent as far as we can accept, and we expand axioms to overcome limitations [Koellner]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / g. Incompleteness of Arithmetic
Arithmetical undecidability is always settled at the next stage up [Koellner]
8. Modes of Existence / B. Properties / 4. Intrinsic Properties
We must avoid circularity between what is intrinsic and what is natural [Lewis, by Cameron]
A property is 'intrinsic' iff it can never differ between duplicates [Lewis]
Ellipsoidal stars seem to have an intrinsic property which depends on other objects [Lewis]
14. Science / D. Explanation / 2. Types of Explanation / g. Causal explanations
Geometrical proofs do not show causes, as when we prove a triangle contains two right angles [Proclus]
18. Thought / E. Abstraction / 1. Abstract Thought
The origin of geometry started in sensation, then moved to calculation, and then to reason [Proclus]