Combining Texts

All the ideas for 'The Sign of Four', 'Higher-Order Logic' and 'Gorgias'

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39 ideas

1. Philosophy / D. Nature of Philosophy / 7. Despair over Philosophy
Is a gifted philosopher unmanly if he avoids the strife of the communal world? [Plato]
2. Reason / C. Styles of Reason / 2. Elenchus
In "Gorgias" Socrates is confident that his 'elenchus' will decide moral truth [Vlastos on Plato]
We should test one another, by asking and answering questions [Plato]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
The axiom of choice is controversial, but it could be replaced [Shapiro]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
First-order logic is Complete, and Compact, with the Löwenheim-Skolem Theorems [Shapiro]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Some say that second-order logic is mathematics, not logic [Shapiro]
If the aim of logic is to codify inferences, second-order logic is useless [Shapiro]
5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence
Logical consequence can be defined in terms of the logical terminology [Shapiro]
5. Theory of Logic / G. Quantification / 5. Second-Order Quantification
Second-order variables also range over properties, sets, relations or functions [Shapiro]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
The Löwenheim-Skolem theorem seems to be a defect of first-order logic [Shapiro]
Up Löwenheim-Skolem: if natural numbers satisfy wffs, then an infinite domain satisfies them [Shapiro]
Downward Löwenheim-Skolem: if there's an infinite model, there is a countable model [Shapiro]
The Löwenheim-Skolem Theorems fail for second-order languages with standard semantics [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / e. Peano arithmetic 2nd-order
Second-order logic has the expressive power for mathematics, but an unworkable model theory [Shapiro]
8. Modes of Existence / B. Properties / 11. Properties as Sets
Logicians use 'property' and 'set' interchangeably, with little hanging on it [Shapiro]
14. Science / C. Induction / 1. Induction
If you eliminate the impossible, the truth will remain, even if it is weird [Conan Doyle]
19. Language / F. Communication / 1. Rhetoric
Rhetoric is irrational about its means and its ends [Plato]
Rhetoric can produce conviction, but not educate people about right and wrong [Plato]
20. Action / B. Preliminaries of Action / 1. Intention to Act / b. Types of intention
All activity aims at the good [Plato]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / g. Will to power
Moral rules are made by the weak members of humanity [Plato]
22. Metaethics / B. Value / 2. Values / h. Fine deeds
A good person is bound to act well, and this brings happiness [Plato]
22. Metaethics / B. Value / 2. Values / i. Self-interest
Is it natural to simply indulge our selfish desires? [Plato]
22. Metaethics / C. The Good / 1. Goodness / f. Good as pleasure
In slaking our thirst the goodness of the action and the pleasure are clearly separate [Plato]
Good should be the aim of pleasant activity, not the other way round [Plato]
22. Metaethics / C. The Good / 3. Pleasure / e. Role of pleasure
Good and bad people seem to experience equal amounts of pleasure and pain [Plato]
22. Metaethics / C. The Good / 3. Pleasure / f. Dangers of pleasure
In a fool's mind desire is like a leaky jar, insatiable in its desires, and order and contentment are better [Plato]
If happiness is the satisfaction of desires, then a life of scratching itches should be happiness [Plato]
23. Ethics / A. Egoism / 2. Hedonism
Is the happiest state one of sensual, self-indulgent freedom? [Plato]
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / c. Motivation for virtue
Should we avoid evil because it will bring us bad consequences? [Plato]
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / e. Character
I would rather be a victim of crime than a criminal [Plato]
23. Ethics / C. Virtue Theory / 3. Virtues / b. Temperance
Self-indulgent desire makes friendship impossible, because it makes a person incapable of co-operation [Plato]
If absence of desire is happiness, then nothing is happier than a stone or a corpse [Plato]
23. Ethics / C. Virtue Theory / 3. Virtues / c. Justice
A criminal is worse off if he avoids punishment [Plato]
Do most people praise self-discipline and justice because they are too timid to gain their own pleasure? [Plato]
23. Ethics / C. Virtue Theory / 4. External Goods / b. Health
The popular view is that health is first, good looks second, and honest wealth third [Plato]
24. Political Theory / B. Nature of a State / 1. Purpose of a State
As with other things, a good state is organised and orderly [Plato]
24. Political Theory / D. Ideologies / 5. Democracy / c. Direct democracy
A good citizen won't be passive, but will redirect the needs of the state [Plato]
25. Social Practice / B. Equalities / 1. Grounds of equality
Do most people like equality because they are second-rate? [Plato]
25. Social Practice / B. Equalities / 4. Economic equality
Does nature imply that it is right for better people to have greater benefits? [Plato]