Combining Texts

All the ideas for 'Theory of Knowledge (2nd edn)', 'Logical Consequence' and 'Proslogion'

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19 ideas

1. Philosophy / C. History of Philosophy / 4. Later European Philosophy / b. Seventeenth century philosophy
Most philosophers start with reality and then examine knowledge; Descartes put the study of knowledge first [Lehrer]
1. Philosophy / F. Analytic Philosophy / 4. Conceptual Analysis
You cannot demand an analysis of a concept without knowing the purpose of the analysis [Lehrer]
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]
28. God / B. Proving God / 2. Proofs of Reason / a. Ontological Proof
An existing thing is even greater if its non-existence is inconceivable [Anselm]
Conceiving a greater being than God leads to absurdity [Anselm]
Even the fool can hold 'a being than which none greater exists' in his understanding [Anselm]
If that than which a greater cannot be thought actually exists, that is greater than the mere idea [Anselm]
A perfection must be independent and unlimited, and the necessary existence of Anselm's second proof gives this [Malcolm on Anselm]
The word 'God' can be denied, but understanding shows God must exist [Anselm]
Guanilo says a supremely fertile island must exist, just because we can conceive it [Anselm]
Nonexistence is impossible for the greatest thinkable thing, which has no beginning or end [Anselm]
28. God / B. Proving God / 2. Proofs of Reason / b. Ontological Proof critique
Anselm's first proof fails because existence isn't a real predicate, so it can't be a perfection [Malcolm on Anselm]