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All the ideas for 'Dissoi Logoi - on Double Arguments', 'What is Logic?' and 'The Putney Debates'

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21 ideas

2. Reason / D. Definition / 3. Types of Definition
A decent modern definition should always imply a semantics [Hacking]
3. Truth / H. Deflationary Truth / 2. Deflationary Truth
True and false statements can use exactly the same words [Anon (Diss)]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / d. Basic theorems of PL
Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking]
Only Cut reduces complexity, so logic is constructive without it, and it can be dispensed with [Hacking]
'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking]
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
The various logics are abstractions made from terms like 'if...then' in English [Hacking]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking]
A limitation of first-order logic is that it cannot handle branching quantifiers [Hacking]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Second-order completeness seems to need intensional entities and possible worlds [Hacking]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
With a pure notion of truth and consequence, the meanings of connectives are fixed syntactically [Hacking]
5. Theory of Logic / E. Structures of Logic / 4. Variables in Logic
Perhaps variables could be dispensed with, by arrows joining places in the scope of quantifiers [Hacking]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking]
13. Knowledge Criteria / E. Relativism / 4. Cultural relativism
Anything can be acceptable in some circumstances and unacceptable in others [Anon (Diss)]
Thracians think tattooing adds to a girl's beauty, but elsewhere it is a punishment [Anon (Diss)]
Lydians prostitute their daughters to raise a dowery, but no Greek would marry such a girl [Anon (Diss)]
20. Action / C. Motives for Action / 3. Acting on Reason / b. Intellectualism
How could someone who knows everything fail to act correctly? [Anon (Diss)]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / j. Ethics by convention
Every apparent crime can be right in certain circumstances [Anon (Diss), by PG]
22. Metaethics / C. The Good / 1. Goodness / g. Consequentialism
It is right to lie to someone, to get them to take medicine they are reluctant to take [Anon (Diss)]
24. Political Theory / B. Nature of a State / 2. State Legitimacy / c. Social contract
Even the poorest have a life to lead, and so should consent to who governs them [-]
24. Political Theory / D. Ideologies / 5. Democracy / b. Consultation
The first priority in elections is to vote for people who support democracy [Anon (Diss)]
25. Social Practice / E. Policies / 5. Education / c. Teaching
We learn language, and we don't know who teaches us it [Anon (Diss)]