Combining Texts

All the ideas for 'Some Puzzles of Ground', 'Philosophy of Logic' and 'On the Cosmos (lost)'

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23 ideas

3. Truth / F. Semantic Truth / 1. Tarski's Truth / a. Tarski's truth definition
18951 For scientific purposes there is a precise concept of 'true-in-L', using set theory [Putnam]
4. Formal Logic / A. Syllogistic Logic / 1. Aristotelian Logic
18953 Modern notation frees us from Aristotle's restriction of only using two class-names in premises [Putnam]
4. Formal Logic / A. Syllogistic Logic / 2. Syllogistic Logic
18949 The universal syllogism is now expressed as the transitivity of subclasses [Putnam]
4. Formal Logic / C. Predicate Calculus PC / 2. Tools of Predicate Calculus / a. Symbols of PC
18952 '⊃' ('if...then') is used with the definition 'Px ⊃ Qx' is short for '¬(Px & ¬Qx)' [Putnam]
4. Formal Logic / E. Nonclassical Logics / 3. Many-Valued Logic
14263 Strong Kleene disjunction just needs one true disjunct; Weak needs the other to have some value [Fine,K]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / a. Types of set
18958 In type theory, 'x ∈ y' is well defined only if x and y are of the appropriate type [Putnam]
5. Theory of Logic / A. Overview of Logic / 2. History of Logic
18954 Before the late 19th century logic was trivialised by not dealing with relations [Putnam]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
18956 Asserting first-order validity implicitly involves second-order reference to classes [Putnam]
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
18962 Unfashionably, I think logic has an empirical foundation [Putnam]
5. Theory of Logic / E. Structures of Logic / 5. Functions in Logic
18961 We can identify functions with certain sets - or identify sets with certain functions [Putnam]
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
18955 Having a valid form doesn't ensure truth, as it may be meaningless [Putnam]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / f. Uncountable infinities
18959 Sets larger than the continuum should be studied in an 'if-then' spirit [Putnam]
7. Existence / C. Structure of Existence / 1. Grounding / a. Nature of grounding
14262 Formal grounding needs transitivity of grounding, no self-grounding, and the existence of both parties [Fine,K]
8. Modes of Existence / E. Nominalism / 1. Nominalism / a. Nominalism
18957 Nominalism only makes sense if it is materialist [Putnam]
9. Objects / A. Existence of Objects / 2. Abstract Objects / b. Need for abstracta
18950 Physics is full of non-physical entities, such as space-vectors [Putnam]
9. Objects / B. Unity of Objects / 1. Unifying an Object / a. Intrinsic unification
472 No things would be clear to us as entity or relationships unless there existed Number and its essence [Philolaus]
14. Science / A. Basis of Science / 4. Prediction
18960 Most predictions are uninteresting, and are only sought in order to confirm a theory [Putnam]
26. Natural Theory / A. Speculations on Nature / 4. Mathematical Nature
1518 Everything must involve numbers, or it couldn't be thought about or known [Philolaus]
1519 Harmony must pre-exist the cosmos, to bring the dissimilar sources together [Philolaus]
473 There is no falsehood in harmony and number, only in irrational things [Philolaus]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / d. The unlimited
469 Existing things, and hence the Cosmos, are a mixture of the Limited and the Unlimited [Philolaus]
26. Natural Theory / D. Laws of Nature / 6. Laws as Numerical
476 Self-created numbers make the universe stable [Philolaus]
27. Natural Reality / E. Cosmology / 1. Cosmology
1787 Philolaus was the first person to say the earth moves in a circle [Philolaus, by Diog. Laertius]