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All the ideas for 'Philosophy of Logics', 'Philosophy of Logic' and 'Philosophy'

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38 ideas

2. Reason / B. Laws of Thought / 3. Non-Contradiction
If you say that a contradiction is true, you change the meaning of 'not', and so change the subject [Quine]
3. Truth / A. Truth Problems / 4. Uses of Truth
Truth is what unites, and the profound truths create a community [Jaspers]
3. Truth / C. Correspondence Truth / 3. Correspondence Truth critique
Logical truth seems much less likely to 'correspond to the facts' than factual truth does [Haack]
3. Truth / F. Semantic Truth / 1. Tarski's Truth / a. Tarski's truth definition
The same sentence could be true in one language and meaningless in another, so truth is language-relative [Haack]
3. Truth / F. Semantic Truth / 2. Semantic Truth
Talk of 'truth' when sentences are mentioned; it reminds us that reality is the point of sentences [Quine]
3. Truth / H. Deflationary Truth / 1. Redundant Truth
Truth is redundant for single sentences; we do better to simply speak the sentence [Quine]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / e. Axioms of PL
We can eliminate 'or' from our basic theory, by paraphrasing 'p or q' as 'not(not-p and not-q)' [Quine]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
My logical grammar has sentences by predication, then negation, conjunction, and existential quantification [Quine]
5. Theory of Logic / A. Overview of Logic / 3. Value of Logic
Maybe logical truth reflects reality, but in different ways in different languages [Quine]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Quine rejects second-order logic, saying that predicates refer to multiple objects [Quine, by Hodes]
Quantifying over predicates is treating them as names of entities [Quine]
5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle
Excluded middle has three different definitions [Quine]
5. Theory of Logic / D. Assumptions for Logic / 4. Identity in Logic
Quantification theory can still be proved complete if we add identity [Quine]
5. Theory of Logic / F. Referring in Logic / 1. Naming / f. Names eliminated
Names are not essential, because naming can be turned into predication [Quine]
5. Theory of Logic / G. Quantification / 1. Quantification
Universal quantification is widespread, but it is definable in terms of existential quantification [Quine]
5. Theory of Logic / G. Quantification / 4. Substitutional Quantification
You can't base quantification on substituting names for variables, if the irrationals cannot all be named [Quine]
Some quantifications could be false substitutionally and true objectually, because of nameless objects [Quine]
5. Theory of Logic / G. Quantification / 5. Second-Order Quantification
Putting a predicate letter in a quantifier is to make it the name of an entity [Quine]
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
A sentence is logically true if all sentences with that grammatical structure are true [Quine]
8. Modes of Existence / B. Properties / 12. Denial of Properties
Predicates are not names; predicates are the other parties to predication [Quine]
9. Objects / A. Existence of Objects / 1. Physical Objects
A physical object is the four-dimensional material content of a portion of space-time [Quine]
9. Objects / E. Objects over Time / 4. Four-Dimensionalism
Four-d objects helps predication of what no longer exists, and quantification over items from different times [Quine]
10. Modality / B. Possibility / 8. Conditionals / b. Types of conditional
Some conditionals can be explained just by negation and conjunction: not(p and not-q) [Quine]
16. Persons / F. Free Will / 2. Sources of Free Will
Freedom needs knowledge, the possibility of arbitrariness, and law [Jaspers]
16. Persons / F. Free Will / 4. For Free Will
I am aware that freedom is possible, and the freedom is not in theory, but in seeking freedom [Jaspers]
19. Language / A. Nature of Meaning / 8. Synonymy
Single words are strongly synonymous if their interchange preserves truth [Quine]
19. Language / D. Propositions / 6. Propositions Critique
It makes no sense to say that two sentences express the same proposition [Quine]
There is no rule for separating the information from other features of sentences [Quine]
We can abandon propositions, and just talk of sentences and equivalence [Quine]
19. Language / F. Communication / 5. Pragmatics / a. Contextual meaning
A good way of explaining an expression is saying what conditions make its contexts true [Quine]
20. Action / C. Motives for Action / 4. Responsibility for Actions
My freedom increases as I broaden my vision of possiblities and motives [Jaspers]
23. Ethics / F. Existentialism / 1. Existentialism
My helplessness in philosophising reveals my being, and begins its upsurge [Jaspers]
The struggle for Existenz is between people who are equals, and are utterly honest [Jaspers]
Once we grasp freedom 'from' things, then freedom 'for' things becomes urgent [Jaspers]
23. Ethics / F. Existentialism / 6. Authentic Self
Mundane existence is general, falling under universals, but Existens is unique to individuals [Jaspers]
We want the correct grasp on being that is neither solipsism nor absorption in the crowd [Jaspers]
'Existenz' is the potential being, which I could have, and ought to have [Jaspers]
23. Ethics / F. Existentialism / 7. Existential Action
Every decision I make moves towards or away from fulfilled Existenz [Jaspers]