Combining Philosophers

All the ideas for Xenophanes, Rod Girle and Bert Leuridan

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


32 ideas

4. Formal Logic / B. Propositional Logic PL / 1. Propositional Logic
There are three axiom schemas for propositional logic [Girle]
Propositional logic handles negation, disjunction, conjunction; predicate logic adds quantifiers, predicates, relations [Girle]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / a. Symbols of PL
Proposition logic has definitions for its three operators: or, and, and identical [Girle]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / e. Axioms of PL
Axiom systems of logic contain axioms, inference rules, and definitions of proof and theorems [Girle]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / g. System S4
There are seven modalities in S4, each with its negation [Girle]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
◊p → □◊p is the hallmark of S5 [Girle]
S5 has just six modalities, and all strings can be reduced to those [Girle]
4. Formal Logic / D. Modal Logic ML / 4. Alethic Modal Logic
Possible worlds logics use true-in-a-world rather than true [Girle]
Modal logics were studied in terms of axioms, but now possible worlds semantics is added [Girle]
Modal logic has four basic modal negation equivalences [Girle]
5. Theory of Logic / B. Logical Consequence / 7. Strict Implication
Necessary implication is called 'strict implication'; if successful, it is called 'entailment' [Girle]
5. Theory of Logic / H. Proof Systems / 5. Tableau Proof
If an argument is invalid, a truth tree will indicate a counter-example [Girle]
10. Modality / A. Necessity / 3. Types of Necessity
Analytic truths are divided into logically and conceptually necessary [Girle]
10. Modality / B. Possibility / 1. Possibility
Possibilities can be logical, theoretical, physical, economic or human [Girle]
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
A world has 'access' to a world it generates, which is important in possible worlds semantics [Girle]
13. Knowledge Criteria / D. Scepticism / 1. Scepticism
If we succeed in speaking the truth, we cannot know we have done it [Xenophanes]
13. Knowledge Criteria / E. Relativism / 1. Relativism
If God had not created honey, men would say figs are sweeter [Xenophanes]
14. Science / D. Explanation / 2. Types of Explanation / e. Lawlike explanations
Generalisations must be invariant to explain anything [Leuridan]
14. Science / D. Explanation / 2. Types of Explanation / h. Explanations by function
Biological functions are explained by disposition, or by causal role [Leuridan]
14. Science / D. Explanation / 2. Types of Explanation / i. Explanations by mechanism
Mechanisms are ontologically dependent on regularities [Leuridan]
Mechanisms can't explain on their own, as their models rest on pragmatic regularities [Leuridan]
We can show that regularities and pragmatic laws are more basic than mechanisms [Leuridan]
Mechanisms must produce macro-level regularities, but that needs micro-level regularities [Leuridan]
14. Science / D. Explanation / 3. Best Explanation / b. Ultimate explanation
There is nothing wrong with an infinite regress of mechanisms and regularities [Leuridan]
26. Natural Theory / A. Speculations on Nature / 3. Natural Function
Rather than dispositions, functions may be the element that brought a thing into existence [Leuridan]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / e. The One
The basic Eleatic belief was that all things are one [Xenophanes, by Plato]
26. Natural Theory / D. Laws of Nature / 3. Laws and Generalities
Pragmatic laws allow prediction and explanation, to the extent that reality is stable [Leuridan]
26. Natural Theory / D. Laws of Nature / 4. Regularities / a. Regularity theory
Strict regularities are rarely discovered in life sciences [Leuridan]
26. Natural Theory / D. Laws of Nature / 11. Against Laws of Nature
A 'law of nature' is just a regularity, not some entity that causes the regularity [Leuridan]
28. God / A. Divine Nature / 2. Divine Nature
Xenophanes said the essence of God was spherical and utterly inhuman [Xenophanes, by Diog. Laertius]
28. God / C. Attitudes to God / 5. Atheism
Mortals believe gods are born, and have voices and clothes just like mortals [Xenophanes]
Ethiopian gods have black hair, and Thracian gods have red hair [Xenophanes]