Combining Philosophers

All the ideas for Carneades, Wilfrid Hodges and Gonzalo Rodriguez-Pereyra

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

28 ideas

1. Philosophy / D. Nature of Philosophy / 3. Philosophy Defined
Carneades' pinnacles of philosophy are the basis of knowledge (the criterion of truth) and the end of appetite (good) [Carneades, by Cicero]
2. Reason / D. Definition / 7. Contextual Definition
The idea that groups of concepts could be 'implicitly defined' was abandoned [Hodges,W]
3. Truth / B. Truthmakers / 10. Making Future Truths
Future events are true if one day we will say 'this event is happening now' [Carneades]
We say future things are true that will possess actuality at some following time [Carneades, by Cicero]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
Logic is the study of sound argument, or of certain artificial languages (or applying the latter to the former) [Hodges,W]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
Since first-order languages are complete, |= and |- have the same meaning [Hodges,W]
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
|= in model-theory means 'logical consequence' - it holds in all models [Hodges,W]
5. Theory of Logic / I. Semantics of Logic / 1. Semantics of Logic
There are three different standard presentations of semantics [Hodges,W]
A formula needs an 'interpretation' of its constants, and a 'valuation' of its variables [Hodges,W]
I |= φ means that the formula φ is true in the interpretation I [Hodges,W]
5. Theory of Logic / I. Semantics of Logic / 4. Satisfaction
|= should be read as 'is a model for' or 'satisfies' [Hodges,W]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
Model theory studies formal or natural language-interpretation using set-theory [Hodges,W]
Models in model theory are structures, not sets of descriptions [Hodges,W]
A 'structure' is an interpretation specifying objects and classes of quantification [Hodges,W]
5. Theory of Logic / J. Model Theory in Logic / 3. L÷wenheim-Skolem Theorems
Down L÷wenheim-Skolem: if a countable language has a consistent theory, that has a countable model [Hodges,W]
Up L÷wenheim-Skolem: if infinite models, then arbitrarily large models [Hodges,W]
5. Theory of Logic / K. Features of Logics / 6. Compactness
If a first-order theory entails a sentence, there is a finite subset of the theory which entails it [Hodges,W]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / i. Cardinal infinity
First-order logic can't discriminate between one infinite cardinal and another [Hodges,W]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
A 'set' is a mathematically well-behaved class [Hodges,W]
8. Modes of Existence / E. Nominalism / 2. Resemblance Nominalism
Resemblance Nominalists say that resemblance explains properties (not the other way round) [Rodriquez-Pereyra]
Entities are truthmakers for their resemblances, so no extra entities or 'resemblances' are needed [Rodriquez-Pereyra]
9. Objects / F. Identity among Objects / 6. Identity between Objects
Carneades denied the transitivity of identity [Carneades, by Chisholm]
10. Modality / A. Necessity / 3. Types of Necessity
Carneades distinguished logical from causal necessity, when talking of future events [Long on Carneades]
16. Persons / F. Free Will / 2. Sources of Free Will
Voluntary motion is intrinsically within our power, and this power is its cause [Carneades, by Cicero]
16. Persons / F. Free Will / 6. Determinism / a. Determinism
Some actions are within our power; determinism needs prior causes for everything - so it is false [Carneades, by Cicero]
16. Persons / F. Free Will / 6. Determinism / b. Fate
Even Apollo can only foretell the future when it is naturally necessary [Carneades, by Cicero]
22. Metaethics / A. Value / 2. Values / h. Self interest
Carneades said that after a shipwreck a wise man would seize the only plank by force [Carneades, by Tuck]
25. Social Practice / D. Justice / 1. Basis of justice
People change laws for advantage; either there is no justice, or it is a form of self-injury [Carneades, by Lactantius]