Combining Philosophers

All the ideas for Xenophanes, George Boole and Thrasymachus

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11 ideas

4. Formal Logic / B. Propositional Logic PL / 1. Propositional Logic
Boole applied normal algebra to logic, aiming at an algebra of thought [Boole, by Devlin]
Boole's notation can represent syllogisms and propositional arguments, but not both at once [Boole, by Weiner]
5. Theory of Logic / A. Overview of Logic / 2. History of Logic
Boole made logic more mathematical, with algebra, quantifiers and probability [Boole, by Friend]
5. Theory of Logic / H. Proof Systems / 2. Axiomatic Proof
Boole's method was axiomatic, achieving economy, plus multiple interpretations [Boole, by Potter]
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]
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]
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 / 3. Deism
Clearly the gods ignore human affairs, or they would have given us justice [Thrasymachus]
28. God / C. Attitudes to God / 5. Atheism
Ethiopian gods have black hair, and Thracian gods have red hair [Xenophanes]
Mortals believe gods are born, and have voices and clothes just like mortals [Xenophanes]