Combining Texts

All the ideas for 'Which Logic is the Right Logic?', 'Intro to 'Provenance of Pure Reason'' and 'Rules for the Direction of the Mind'

expand these ideas     |    start again     |     specify just one area for these texts


36 ideas

1. Philosophy / D. Nature of Philosophy / 7. Despair over Philosophy
Clever scholars can obscure things which are obvious even to peasants [Descartes]
1. Philosophy / F. Analytic Philosophy / 5. Linguistic Analysis
Most scholastic disputes concern words, where agreeing on meanings would settle them [Descartes]
2. Reason / A. Nature of Reason / 4. Aims of Reason
The secret of the method is to recognise which thing in a series is the simplest [Descartes]
2. Reason / A. Nature of Reason / 5. Objectivity
One truth leads us to another [Descartes]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
The axiom of choice now seems acceptable and obvious (if it is meaningful) [Tharp]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
Logic is either for demonstration, or for characterizing structures [Tharp]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
Elementary logic is complete, but cannot capture mathematics [Tharp]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Second-order logic isn't provable, but will express set-theory and classic problems [Tharp]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / b. Basic connectives
In sentential logic there is a simple proof that all truth functions can be reduced to 'not' and 'and' [Tharp]
5. Theory of Logic / G. Quantification / 2. Domain of Quantification
The main quantifiers extend 'and' and 'or' to infinite domains [Tharp]
5. Theory of Logic / G. Quantification / 7. Unorthodox Quantification
There are at least five unorthodox quantifiers that could be used [Tharp]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
Skolem mistakenly inferred that Cantor's conceptions were illusory [Tharp]
The Löwenheim-Skolem property is a limitation (e.g. can't say there are uncountably many reals) [Tharp]
5. Theory of Logic / K. Features of Logics / 1. Axiomatisation
Mathematics must be based on axioms, which are true because they are axioms, not vice versa [Tait, by Parsons,C]
5. Theory of Logic / K. Features of Logics / 3. Soundness
Soundness would seem to be an essential requirement of a proof procedure [Tharp]
5. Theory of Logic / K. Features of Logics / 4. Completeness
Completeness and compactness together give axiomatizability [Tharp]
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
If completeness fails there is no algorithm to list the valid formulas [Tharp]
5. Theory of Logic / K. Features of Logics / 6. Compactness
Compactness is important for major theories which have infinitely many axioms [Tharp]
Compactness blocks infinite expansion, and admits non-standard models [Tharp]
5. Theory of Logic / K. Features of Logics / 8. Enumerability
A complete logic has an effective enumeration of the valid formulas [Tharp]
Effective enumeration might be proved but not specified, so it won't guarantee knowledge [Tharp]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / a. Units
Unity is something shared by many things, so in that respect they are equals [Descartes]
I can only see the proportion of two to three if there is a common measure - their unity [Descartes]
7. Existence / A. Nature of Existence / 3. Being / d. Non-being
Among the simples are the graspable negations, such as rest and instants [Descartes]
10. Modality / C. Sources of Modality / 4. Necessity from Concepts
3+4=7 is necessary because we cannot conceive of seven without including three and four [Descartes]
11. Knowledge Aims / B. Certain Knowledge / 1. Certainty
If we accept mere probabilities as true we undermine our existing knowledge [Descartes]
11. Knowledge Aims / B. Certain Knowledge / 4. The Cogito
We all see intuitively that we exist, where intuition is attentive, clear and distinct rational understanding [Descartes]
When Socrates doubts, he know he doubts, and that truth is possible [Descartes]
12. Knowledge Sources / A. A Priori Knowledge / 2. Self-Evidence
Clear and distinct truths must be known all at once (unlike deductions) [Descartes]
12. Knowledge Sources / A. A Priori Knowledge / 3. Innate Knowledge / a. Innate knowledge
Our souls possess divine seeds of knowledge, which can bear spontaneous fruit [Descartes]
12. Knowledge Sources / D. Empiricism / 5. Empiricism Critique
If someone had only seen the basic colours, they could deduce the others from resemblance [Descartes]
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / a. Foundationalism
The method starts with clear intuitions, followed by a process of deduction [Descartes]
15. Nature of Minds / A. Nature of Mind / 8. Brain
Nerves and movement originate in the brain, where imagination moves them [Descartes]
15. Nature of Minds / C. Capacities of Minds / 1. Faculties
Our four knowledge faculties are intelligence, imagination, the senses, and memory [Descartes]
17. Mind and Body / A. Mind-Body Dualism / 1. Dualism
The force by which we know things is spiritual, and quite distinct from the body [Descartes]
26. Natural Theory / A. Speculations on Nature / 4. Mathematical Nature
All the sciences searching for order and measure are related to mathematics [Descartes]