Combining Texts

All the ideas for 'Logical Consequence', 'Extrinsic Properties' and 'Notebooks 1914-1916'

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20 ideas

1. Philosophy / F. Analytic Philosophy / 5. Linguistic Analysis
Analysis complicates a statement, but only as far as the complexity of its meaning [Wittgenstein]
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 / 1. Overview of Logic
We can dispense with self-evidence, if language itself prevents logical mistakes [Jeshion on Wittgenstein]
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 / E. Structures of Logic / 1. Logical Form
A statement's logical form derives entirely from its constituents [Wittgenstein]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
'And' and 'not' are non-referring terms, which do not represent anything [Wittgenstein, by Fogelin]
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]
7. Existence / C. Structure of Existence / 6. Fundamentals / d. Logical atoms
The sense of propositions relies on the world's basic logical structure [Wittgenstein]
8. Modes of Existence / B. Properties / 4. Intrinsic Properties
Being alone doesn't guarantee intrinsic properties; 'being alone' is itself extrinsic [Lewis, by Sider]
Extrinsic properties come in degrees, with 'brother' less extrinsic than 'sibling' [Lewis]
9. Objects / A. Existence of Objects / 5. Individuation / b. Individuation by properties
Total intrinsic properties give us what a thing is [Lewis]
12. Knowledge Sources / A. A Priori Knowledge / 5. A Priori Synthetic
My main problem is the order of the world, and whether it is knowable a priori [Wittgenstein]
16. Persons / B. Nature of the Self / 4. Presupposition of Self
The philosophical I is the metaphysical subject, the limit - not a part of the world [Wittgenstein]
19. Language / A. Nature of Meaning / 2. Meaning as Mental
Propositions assemble a world experimentally, like the model of a road accident [Wittgenstein]
25. Social Practice / F. Life Issues / 4. Suicide
Absolute prohibitions are the essence of ethics, and suicide is the most obvious example [Wittgenstein]