Combining Philosophers

All the ideas for Proclus, Jennifer Fisher and Peter Geach

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39 ideas

2. Reason / A. Nature of Reason / 1. On Reason
We reach 'reflective equilibrium' when intuitions and theory completely align [Fisher]
4. Formal Logic / E. Nonclassical Logics / 3. Many-Valued Logic
Three-valued logic says excluded middle and non-contradition are not tautologies [Fisher]
4. Formal Logic / E. Nonclassical Logics / 4. Fuzzy Logic
Fuzzy logic has many truth values, ranging in fractions from 0 to 1 [Fisher]
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
Classical logic is: excluded middle, non-contradiction, contradictions imply all, disjunctive syllogism [Fisher]
5. Theory of Logic / C. Ontology of Logic / 2. Platonism in Logic
Logic formalizes how we should reason, but it shouldn't determine whether we are realists [Fisher]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / d. Counting via concepts
Are 'word token' and 'word type' different sorts of countable objects, or two ways of counting? [Geach, by Perry]
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / c. Against mathematical empiricism
Abstraction from objects won't reveal an operation's being performed 'so many times' [Geach]
7. Existence / D. Theories of Reality / 10. Vagueness / g. Degrees of vagueness
We could make our intuitions about heaps precise with a million-valued logic [Fisher]
8. Modes of Existence / B. Properties / 10. Properties as Predicates
Attributes are functions, not objects; this distinguishes 'square of 2' from 'double of 2' [Geach]
9. Objects / A. Existence of Objects / 6. Nihilism about Objects
We should abandon absolute identity, confining it to within some category [Geach, by Hawthorne]
9. Objects / B. Unity of Objects / 3. Unity Problems / e. Vague objects
Vagueness can involve components (like baldness), or not (like boredom) [Fisher]
9. Objects / F. Identity among Objects / 3. Relative Identity
Denial of absolute identity has drastic implications for logic, semantics and set theory [Wasserman on Geach]
Identity is relative. One must not say things are 'the same', but 'the same A as' [Geach]
9. Objects / F. Identity among Objects / 8. Leibniz's Law
Leibniz's Law is incomplete, since it includes a non-relativized identity predicate [Geach, by Wasserman]
9. Objects / F. Identity among Objects / 9. Sameness
Being 'the same' is meaningless, unless we specify 'the same X' [Geach]
10. Modality / B. Possibility / 1. Possibility
We can't explain 'possibility' in terms of 'possible' worlds [Fisher]
10. Modality / B. Possibility / 8. Conditionals / c. Truth-function conditionals
If all truths are implied by a falsehood, then not-p might imply both q and not-q [Fisher]
10. Modality / B. Possibility / 8. Conditionals / d. Non-truthfunction conditionals
In relevance logic, conditionals help information to flow from antecedent to consequent [Fisher]
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]
15. Nature of Minds / C. Capacities of Minds / 3. Abstraction by mind
A big flea is a small animal, so 'big' and 'small' cannot be acquired by abstraction [Geach]
We cannot learn relations by abstraction, because their converse must be learned too [Geach]
15. Nature of Minds / C. Capacities of Minds / 5. Generalisation by mind
If concepts are just recognitional, then general judgements would be impossible [Geach]
17. Mind and Body / B. Behaviourism / 2. Potential Behaviour
You can't define real mental states in terms of behaviour that never happens [Geach]
17. Mind and Body / B. Behaviourism / 4. Behaviourism Critique
Beliefs aren't tied to particular behaviours [Geach]
18. Thought / D. Concepts / 2. Origin of Concepts / a. Origin of concepts
The mind does not lift concepts from experience; it creates them, and then applies them [Geach]
18. Thought / D. Concepts / 3. Ontology of Concepts / b. Concepts as abilities
For abstractionists, concepts are capacities to recognise recurrent features of the world [Geach]
18. Thought / D. Concepts / 5. Concepts and Language / c. Concepts without language
If someone has aphasia but can still play chess, they clearly have concepts [Geach]
18. Thought / E. Abstraction / 1. Abstract Thought
The origin of geometry started in sensation, then moved to calculation, and then to reason [Proclus]
18. Thought / E. Abstraction / 3. Abstracta by Ignoring
'Abstractionism' is acquiring a concept by picking out one experience amongst a group [Geach]
18. Thought / E. Abstraction / 8. Abstractionism Critique
'Or' and 'not' are not to be found in the sensible world, or even in the world of inner experience [Geach]
We can't acquire number-concepts by extracting the number from the things being counted [Geach]
Abstractionists can't explain counting, because it must precede experience of objects [Geach]
The numbers don't exist in nature, so they cannot have been abstracted from there into our languages [Geach]
Blind people can use colour words like 'red' perfectly intelligently [Geach]
If 'black' and 'cat' can be used in the absence of such objects, how can such usage be abstracted? [Geach]
We can form two different abstract concepts that apply to a single unified experience [Geach]
The abstractionist cannot explain 'some' and 'not' [Geach]
Only a judgement can distinguish 'striking' from 'being struck' [Geach]
22. Metaethics / C. The Good / 1. Goodness / a. Form of the Good
'Good' is an attributive adjective like 'large', not predicative like 'red' [Geach, by Foot]