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All the ideas for 'What is Logic?st1=Ian Hacking', 'Identity and Essence' and 'Reason, Truth and History'

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46 ideas

1. Philosophy / A. Wisdom / 1. Nature of Wisdom
For ancient Greeks being wise was an ethical value [Putnam]
2. Reason / D. Definition / 3. Types of Definition
A decent modern definition should always imply a semantics [Hacking]
3. Truth / A. Truth Problems / 1. Truth
Putnam's epistemic notion of truth replaces the realism of correspondence with ontological relativism [Putnam, by O'Grady]
3. Truth / C. Correspondence Truth / 1. Correspondence Truth
Before Kant, all philosophers had a correspondence theory of truth [Putnam]
3. Truth / C. Correspondence Truth / 3. Correspondence Truth critique
The correspondence theory is wrong, because there is no one correspondence between reality and fact [Putnam, by O'Grady]
3. Truth / E. Pragmatic Truth / 1. Pragmatic Truth
Truth is an idealisation of rational acceptability [Putnam]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / d. Basic theorems of PL
'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking]
Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking]
Only Cut reduces complexity, so logic is constructive without it, and it can be dispensed with [Hacking]
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
The various logics are abstractions made from terms like 'if...then' in English [Hacking]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking]
A limitation of first-order logic is that it cannot handle branching quantifiers [Hacking]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Second-order completeness seems to need intensional entities and possible worlds [Hacking]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
With a pure notion of truth and consequence, the meanings of connectives are fixed syntactically [Hacking]
5. Theory of Logic / E. Structures of Logic / 4. Variables in Logic
Perhaps variables could be dispensed with, by arrows joining places in the scope of quantifiers [Hacking]
5. Theory of Logic / I. Semantics of Logic / 6. Intensionalism
Intension is not meaning, as 'cube' and 'square-faced polyhedron' are intensionally the same [Putnam]
5. Theory of Logic / J. Model Theory in Logic / 2. Isomorphisms
If cats equal cherries, model theory allows reinterpretation of the whole language preserving truth [Putnam]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking]
7. Existence / D. Theories of Reality / 4. Anti-realism
If we try to cure the abundance of theories with causal links, this is 'just more theory' [Putnam, by Lewis]
The sentence 'A cat is on a mat' remains always true when 'cat' means cherry and 'mat' means tree [Putnam]
7. Existence / D. Theories of Reality / 8. Facts / a. Facts
A fact is simply what it is rational to accept [Putnam]
8. Modes of Existence / B. Properties / 12. Denial of Properties
Very nominalistic philosophers deny properties, though scientists accept them [Putnam]
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
Indiscernibility is a necessary and sufficient condition for identity [Brody]
9. Objects / A. Existence of Objects / 5. Individuation / e. Individuation by kind
Brody bases sortal essentialism on properties required throughout something's existence [Brody, by Mackie,P]
9. Objects / C. Structure of Objects / 2. Hylomorphism / a. Hylomorphism
Modern emphasis is on properties had essentially; traditional emphasis is on sort-defining properties [Brody]
9. Objects / D. Essence of Objects / 5. Essence as Kind
A sortal essence is a property which once possessed always possessed [Brody, by Mackie,P]
Maybe essential properties are those which determine a natural kind? [Brody]
9. Objects / D. Essence of Objects / 6. Essence as Unifier
De re essentialism standardly says all possible objects identical with a have a's essential properties [Brody]
9. Objects / D. Essence of Objects / 7. Essence and Necessity / a. Essence as necessary properties
Essentially, a has P, always had P, must have had P, and has never had a future without P [Brody]
An object having a property essentially is equivalent to its having it necessarily [Brody]
9. Objects / D. Essence of Objects / 8. Essence as Explanatory
Essentialism is justified if the essential properties of things explain their other properties [Brody]
9. Objects / D. Essence of Objects / 12. Essential Parts
Mereological essentialism says that every part that ensures the existence is essential [Brody]
9. Objects / E. Objects over Time / 12. Origin as Essential
Interrupted objects have two first moments of existence, which could be two beginnings [Brody]
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
a and b share all properties; so they share being-identical-with-a; so a = b [Brody]
10. Modality / A. Necessity / 11. Denial of Necessity
If necessity is always relative to a description in a language, then there is only 'de dicto' necessity [Putnam, by O'Grady]
10. Modality / E. Possible worlds / 3. Transworld Objects / b. Rigid designation
Identity across possible worlds is prior to rigid designation [Brody]
13. Knowledge Criteria / E. Relativism / 6. Relativism Critique
Some kind of objective 'rightness' is a presupposition of thought itself [Putnam]
14. Science / B. Scientific Theories / 3. Instrumentalism
Naïve operationalism would have meanings change every time the tests change [Putnam]
18. Thought / A. Modes of Thought / 5. Rationality / b. Human rationality
Rationality is one part of our conception of human flourishing [Putnam]
18. Thought / C. Content / 5. Twin Earth
'Water' on Twin Earth doesn't refer to water, but no mental difference can account for this [Putnam]
18. Thought / C. Content / 6. Broad Content
Reference is social not individual, because we defer to experts when referring to elm trees [Putnam]
18. Thought / D. Concepts / 3. Ontology of Concepts / b. Concepts as abilities
Concepts are (at least in part) abilities and not occurrences [Putnam]
19. Language / B. Reference / 3. Direct Reference / c. Social reference
Neither individual nor community mental states fix reference [Putnam]
Maybe the total mental state of a language community fixes the reference of a term [Putnam]
19. Language / F. Communication / 6. Interpreting Language / b. Indeterminate translation
There are infinitely many interpretations of a sentence which can all seem to be 'correct' [Putnam]
22. Metaethics / B. Value / 1. Nature of Value / b. Fact and value
The word 'inconsiderate' nicely shows the blurring of facts and values [Putnam]