Combining Texts

All the ideas for 'Leibniz', 'Rules for the Direction of the Mind' and 'Philosophy of Logic'

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34 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]
3. Truth / F. Semantic Truth / 1. Tarski's Truth / a. Tarski's truth definition
For scientific purposes there is a precise concept of 'true-in-L', using set theory [Putnam]
4. Formal Logic / A. Syllogistic Logic / 1. Aristotelian Logic
Modern notation frees us from Aristotle's restriction of only using two class-names in premises [Putnam]
4. Formal Logic / A. Syllogistic Logic / 2. Syllogistic Logic
The universal syllogism is now expressed as the transitivity of subclasses [Putnam]
4. Formal Logic / C. Predicate Calculus PC / 2. Tools of Predicate Calculus / a. Symbols of PC
'⊃' ('if...then') is used with the definition 'Px ⊃ Qx' is short for '¬(Px & ¬Qx)' [Putnam]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / a. Types of set
In type theory, 'x ∈ y' is well defined only if x and y are of the appropriate type [Putnam]
5. Theory of Logic / A. Overview of Logic / 2. History of Logic
Before the late 19th century logic was trivialised by not dealing with relations [Putnam]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
Asserting first-order validity implicitly involves second-order reference to classes [Putnam]
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
Unfashionably, I think logic has an empirical foundation [Putnam]
5. Theory of Logic / E. Structures of Logic / 5. Functions in Logic
We can identify functions with certain sets - or identify sets with certain functions [Putnam]
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
Having a valid form doesn't ensure truth, as it may be meaningless [Putnam]
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]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / f. Uncountable infinities
Sets larger than the continuum should be studied in an 'if-then' spirit [Putnam]
7. Existence / A. Nature of Existence / 3. Being / d. Non-being
Among the simples are the graspable negations, such as rest and instants [Descartes]
8. Modes of Existence / E. Nominalism / 1. Nominalism / a. Nominalism
Nominalism only makes sense if it is materialist [Putnam]
9. Objects / A. Existence of Objects / 2. Abstract Objects / b. Need for abstracta
Physics is full of non-physical entities, such as space-vectors [Putnam]
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
The Identity of Indiscernibles is really the same as the verification principle [Jolley]
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]
14. Science / A. Basis of Science / 4. Prediction
Most predictions are uninteresting, and are only sought in order to confirm a theory [Putnam]
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]