Combining Texts

All the ideas for 'Universal Prescriptivism', 'The Problem of Knowledge' and 'Logical Necessity'

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27 ideas

2. Reason / F. Fallacies / 1. Fallacy
Induction assumes some uniformity in nature, or that in some respects the future is like the past [Ayer]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
The logic of metaphysical necessity is S5 [Rumfitt]
5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence
Soundness in argument varies with context, and may be achieved very informally indeed [Rumfitt]
There is a modal element in consequence, in assessing reasoning from suppositions [Rumfitt]
We reject deductions by bad consequence, so logical consequence can't be deduction [Rumfitt]
5. Theory of Logic / D. Assumptions for Logic / 3. Contradiction
Contradictions include 'This is red and not coloured', as well as the formal 'B and not-B' [Rumfitt]
5. Theory of Logic / H. Proof Systems / 2. Axiomatic Proof
Geometrical axioms in logic are nowadays replaced by inference rules (which imply the logical truths) [Rumfitt]
10. Modality / A. Necessity / 3. Types of Necessity
A distinctive type of necessity is found in logical consequence [Rumfitt, by Hale/Hoffmann,A]
10. Modality / A. Necessity / 6. Logical Necessity
Logical necessity is when 'necessarily A' implies 'not-A is contradictory' [Rumfitt]
A logically necessary statement need not be a priori, as it could be unknowable [Rumfitt]
Narrow non-modal logical necessity may be metaphysical, but real logical necessity is not [Rumfitt]
10. Modality / E. Possible worlds / 1. Possible Worlds / e. Against possible worlds
If a world is a fully determinate way things could have been, can anyone consider such a thing? [Rumfitt]
11. Knowledge Aims / B. Certain Knowledge / 5. Cogito Critique
Knowing I exist reveals nothing at all about my nature [Ayer]
To say 'I am not thinking' must be false, but it might have been true, so it isn't self-contradictory [Ayer]
'I know I exist' has no counterevidence, so it may be meaningless [Ayer]
14. Science / A. Basis of Science / 6. Falsification
We only discard a hypothesis after one failure if it appears likely to keep on failing [Ayer]
14. Science / C. Induction / 2. Aims of Induction
Induction passes from particular facts to other particulars, or to general laws, non-deductively [Ayer]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / c. Ethical intuitionism
How can intuitionists distinguish universal convictions from local cultural ones? [Hare]
You can't use intuitions to decide which intuitions you should cultivate [Hare]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / h. Expressivism
Emotivists mistakenly think all disagreements are about facts, and so there are no moral reasons [Hare]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / i. Prescriptivism
Prescriptivism sees 'ought' statements as imperatives which are universalisable [Hare]
If morality is just a natural or intuitive description, that leads to relativism [Hare]
Descriptivism say ethical meaning is just truth-conditions; prescriptivism adds an evaluation [Hare]
If there can be contradictory prescriptions, then reasoning must be involved [Hare]
An 'ought' statement implies universal application [Hare]
Prescriptivism implies a commitment, but descriptivism doesn't [Hare]
23. Ethics / D. Deontological Ethics / 3. Universalisability
Moral judgements must invoke some sort of principle [Hare]