Combining Texts

All the ideas for 'The Rationality of Science', 'Philosophy of Logic' and 'On Second-Order Logic'

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38 ideas

1. Philosophy / G. Scientific Philosophy / 1. Aims of Science
We do not wish merely to predict, we also want to explain [Newton-Smith]
The real problem of science is how to choose between possible explanations [Newton-Smith]
For science to be rational, we must explain scientific change rationally [Newton-Smith]
1. Philosophy / G. Scientific Philosophy / 2. Positivism
Critics attack positivist division between theory and observation [Newton-Smith]
Positivists hold that theoretical terms change, but observation terms don't [Newton-Smith]
3. Truth / A. Truth Problems / 6. Verisimilitude
More truthful theories have greater predictive power [Newton-Smith]
Theories generate infinite truths and falsehoods, so they cannot be used to assess probability [Newton-Smith]
3. Truth / F. Semantic Truth / 1. Tarski's Truth / a. Tarski's truth definition
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
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
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
'⊃' ('if...then') is used with the definition 'Px ⊃ Qx' is short for '¬(Px & ¬Qx)' [Putnam]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / a. Types of set
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
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
Asserting first-order validity implicitly involves second-order reference to classes [Putnam]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Boolos reinterprets second-order logic as plural logic [Boolos, by Oliver/Smiley]
Second-order logic metatheory is set-theoretic, and second-order validity has set-theoretic problems [Boolos]
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
Unfashionably, I think logic has an empirical foundation [Putnam]
A sentence can't be a truth of logic if it asserts the existence of certain sets [Boolos]
5. Theory of Logic / E. Structures of Logic / 5. Functions in Logic
We can identify functions with certain sets - or identify sets with certain functions [Putnam]
5. Theory of Logic / G. Quantification / 2. Domain of Quantification
'∀x x=x' only means 'everything is identical to itself' if the range of 'everything' is fixed [Boolos]
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
Having a valid form doesn't ensure truth, as it may be meaningless [Putnam]
5. Theory of Logic / K. Features of Logics / 4. Completeness
Weak completeness: if it is valid, it is provable. Strong: it is provable from a set of sentences [Boolos]
5. Theory of Logic / K. Features of Logics / 6. Compactness
Why should compactness be definitive of logic? [Boolos, by Hacking]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / f. Uncountable infinities
Sets larger than the continuum should be studied in an 'if-then' spirit [Putnam]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / e. Peano arithmetic 2nd-order
Many concepts can only be expressed by second-order logic [Boolos]
8. Modes of Existence / E. Nominalism / 1. Nominalism / a. Nominalism
Nominalism only makes sense if it is materialist [Putnam]
9. Objects / A. Existence of Objects / 2. Abstract Objects / b. Need for abstracta
Physics is full of non-physical entities, such as space-vectors [Putnam]
10. Modality / C. Sources of Modality / 1. Sources of Necessity
De re necessity arises from the way the world is [Newton-Smith]
11. Knowledge Aims / A. Knowledge / 4. Belief / a. Beliefs
We must assess the truth of beliefs in identifying them [Newton-Smith]
13. Knowledge Criteria / E. Relativism / 6. Relativism Critique
Defeat relativism by emphasising truth and reference, not meaning [Newton-Smith]
14. Science / A. Basis of Science / 1. Observation
A full understanding of 'yellow' involves some theory [Newton-Smith]
14. Science / A. Basis of Science / 4. Prediction
Most predictions are uninteresting, and are only sought in order to confirm a theory [Putnam]
14. Science / A. Basis of Science / 5. Anomalies
All theories contain anomalies, and so are falsified! [Newton-Smith]
The anomaly of Uranus didn't destroy Newton's mechanics - it led to Neptune's discovery [Newton-Smith]
Anomalies are judged against rival theories, and support for the current theory [Newton-Smith]
14. Science / B. Scientific Theories / 1. Scientific Theory
Why should it matter whether or not a theory is scientific? [Newton-Smith]
14. Science / B. Scientific Theories / 5. Commensurability
If theories are really incommensurable, we could believe them all [Newton-Smith]
20. Action / C. Motives for Action / 3. Acting on Reason / c. Reasons as causes
Explaining an action is showing that it is rational [Newton-Smith]