Combining Philosophers

All the ideas for William S. Jevons, Keith Devlin and G.H. von Wright

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


21 ideas

1. Philosophy / B. History of Ideas / 5. Later European Thought
Logic was merely a branch of rhetoric until the scientific 17th century [Devlin]
4. Formal Logic / A. Syllogistic Logic / 2. Syllogistic Logic
'No councillors are bankers' and 'All bankers are athletes' implies 'Some athletes are not councillors' [Devlin]
4. Formal Logic / B. Propositional Logic PL / 1. Propositional Logic
Modern propositional inference replaces Aristotle's 19 syllogisms with modus ponens [Devlin]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / e. Axioms of PL
Predicate logic retains the axioms of propositional logic [Devlin]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
Situation theory is logic that takes account of context [Devlin]
5. Theory of Logic / A. Overview of Logic / 2. History of Logic
Montague's intensional logic incorporated the notion of meaning [Devlin]
Golden ages: 1900-1960 for pure logic, and 1950-1985 for applied logic [Devlin]
5. Theory of Logic / B. Logical Consequence / 7. Strict Implication
Where a conditional is purely formal, an implication implies a link between premise and conclusion [Devlin]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
Sentences of apparent identical form can have different contextual meanings [Devlin]
5. Theory of Logic / L. Paradox / 4. Paradoxes in Logic / a. Achilles paradox
Space and time are atomic in the arrow, and divisible in the tortoise [Devlin]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / a. Early logicism
I hold that algebra and number are developments of logic [Jevons]
10. Modality / B. Possibility / 1. Possibility
What is true used to be possible, but it may no longer be so [Wright,GHv]
13. Knowledge Criteria / E. Relativism / 5. Language Relativism
People still say the Hopi have no time concepts, despite Whorf's later denial [Devlin]
19. Language / C. Assigning Meanings / 1. Syntax
How do we parse 'time flies like an arrow' and 'fruit flies like an apple'? [Devlin]
19. Language / D. Propositions / 2. Abstract Propositions / a. Propositions as sense
The distinction between sentences and abstract propositions is crucial in logic [Devlin]
26. Natural Theory / C. Causation / 5. Direction of causation
p is a cause and q an effect (not vice versa) if manipulations of p change q [Wright,GHv]
We can imagine controlling floods by controlling rain, but not vice versa [Wright,GHv]
26. Natural Theory / C. Causation / 8. Particular Causation / a. Observation of causation
The very notion of a cause depends on agency and action [Wright,GHv]
We give regularities a causal character by subjecting them to experiment [Wright,GHv]
26. Natural Theory / C. Causation / 8. Particular Causation / c. Conditions of causation
We must further analyse conditions for causation, into quantifiers or modal concepts [Wright,GHv]
26. Natural Theory / D. Laws of Nature / 2. Types of Laws
Some laws are causal (Ohm's Law), but others are conceptual principles (conservation of energy) [Wright,GHv]