Combining Texts

All the ideas for 'Logical Consequence', 'Socrates: Ironist and Moral Philosopher' and 'World and Essence'

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


20 ideas

4. Formal Logic / A. Syllogistic Logic / 2. Syllogistic Logic
'Equivocation' is when terms do not mean the same thing in premises and conclusion [Beall/Restall]
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
Formal logic is invariant under permutations, or devoid of content, or gives the norms for thought [Beall/Restall]
5. Theory of Logic / B. Logical Consequence / 2. Types of Consequence
Logical consequence needs either proofs, or absence of counterexamples [Beall/Restall]
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
Logical consequence is either necessary truth preservation, or preservation based on interpretation [Beall/Restall]
5. Theory of Logic / B. Logical Consequence / 8. Material Implication
A step is a 'material consequence' if we need contents as well as form [Beall/Restall]
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
A 'logical truth' (or 'tautology', or 'theorem') follows from empty premises [Beall/Restall]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
Models are mathematical structures which interpret the non-logical primitives [Beall/Restall]
6. Mathematics / B. Foundations for Mathematics / 2. Proof in Mathematics
Hilbert proofs have simple rules and complex axioms, and natural deduction is the opposite [Beall/Restall]
9. Objects / A. Existence of Objects / 4. Impossible objects
Plantinga proposes necessary existent essences as surrogates for the nonexistent things [Plantinga, by Stalnaker]
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
The 'identity criteria' of a name are a group of essential and established facts [Plantinga]
9. Objects / A. Existence of Objects / 5. Individuation / d. Individuation by haecceity
'Being Socrates' and 'being identical with Socrates' characterise Socrates, so they are among his properties [Plantinga]
9. Objects / D. Essence of Objects / 2. Types of Essence
Does Socrates have essential properties, plus a unique essence (or 'haecceity') which entails them? [Plantinga]
9. Objects / D. Essence of Objects / 9. Essence and Properties
X is essentially P if it is P in every world, or in every X-world, or in the actual world (and not ¬P elsewhere) [Plantinga]
If a property is ever essential, can it only ever be an essential property? [Plantinga]
Essences are instantiated, and are what entails a thing's properties and lack of properties [Plantinga]
Properties are 'trivially essential' if they are instantiated by every object in every possible world [Plantinga]
9. Objects / F. Identity among Objects / 5. Self-Identity
Does 'being identical with Socrates' name a property? I can think of no objections to it [Plantinga]
10. Modality / A. Necessity / 4. De re / De dicto modality
'De re' modality is as clear as 'de dicto' modality, because they are logically equivalent [Plantinga]
10. Modality / D. Knowledge of Modality / 4. Conceivable as Possible / a. Conceivable as possible
We can imagine being beetles or alligators, so it is possible we might have such bodies [Plantinga]
25. Social Practice / D. Justice / 3. Punishment / b. Retribution for crime
In early Greece the word for punishment was also the word for vengeance [Vlastos]