Combining Texts

All the ideas for 'Logical Consequence', 'The Problem of the Essential Indexical' and 'On the Ultimate Origination of Things'

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21 ideas

1. Philosophy / A. Wisdom / 1. Nature of Wisdom
Wisdom involves the desire to achieve perfection [Leibniz]
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]
7. Existence / A. Nature of Existence / 5. Reason for Existence
Leibniz first asked 'why is there something rather than nothing?' [Leibniz, by Jacquette]
There must be a straining towards existence in the essence of all possible things [Leibniz]
Because something does exist, there must be a drive in possible things towards existence [Leibniz]
10. Modality / A. Necessity / 7. Natural Necessity
The world is physically necessary, as its contrary would imply imperfection or moral absurdity [Leibniz]
11. Knowledge Aims / A. Knowledge / 4. Belief / b. Elements of beliefs
Indexicals are a problem for beliefs being just subject-proposition relations [Perry]
19. Language / C. Assigning Meanings / 9. Indexical Semantics
If we replace 'I' in sentences about me, they are different beliefs and explanations of behaviour [Perry]
Indexicals individuate certain belief states, helping in explanation and prediction [Perry]
19. Language / D. Propositions / 6. Propositions Critique
Indexicals reveal big problems with the traditional idea of a proposition [Perry]
20. Action / C. Motives for Action / 3. Acting on Reason / a. Practical reason
We follow the practical rule which always seeks maximum effect for minimum cost [Leibniz]
26. Natural Theory / A. Speculations on Nature / 1. Nature
The principle of determination in things obtains the greatest effect with the least effort [Leibniz]
27. Natural Reality / D. Time / 2. Passage of Time / c. Tenses and time
Tense is essential for thought and action [Perry, by Le Poidevin]
Actual tensed sentences cannot be tenseless, because they can cite their own context [Perry, by Le Poidevin]