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All the ideas for 'Laches', 'Begriffsschrift' and 'Travels in Four Dimensions'

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52 ideas

1. Philosophy / A. Wisdom / 3. Wisdom Deflated
Don't assume that wisdom is the automatic consequence of old age [Plato]
1. Philosophy / F. Analytic Philosophy / 6. Logical Analysis
Frege changed philosophy by extending logic's ability to check the grounds of thinking [Potter on Frege]
2. Reason / B. Laws of Thought / 1. Laws of Thought
We should not describe human laws of thought, but how to correctly track truth [Frege, by Fisher]
4. Formal Logic / C. Predicate Calculus PC / 1. Predicate Calculus PC
I don't use 'subject' and 'predicate' in my way of representing a judgement [Frege]
4. Formal Logic / C. Predicate Calculus PC / 2. Tools of Predicate Calculus / d. Universal quantifier ∀
For Frege, 'All A's are B's' means that the concept A implies the concept B [Frege, by Walicki]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
Frege has a judgement stroke (vertical, asserting or judging) and a content stroke (horizontal, expressing) [Frege, by Weiner]
The laws of logic are boundless, so we want the few whose power contains the others [Frege]
5. Theory of Logic / A. Overview of Logic / 2. History of Logic
In 1879 Frege developed second order logic [Frege, by Putnam]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
Frege replaced Aristotle's subject/predicate form with function/argument form [Frege, by Weiner]
5. Theory of Logic / G. Quantification / 1. Quantification
A quantifier is a second-level predicate (which explains how it contributes to truth-conditions) [Frege, by George/Velleman]
5. Theory of Logic / G. Quantification / 2. Domain of Quantification
For Frege the variable ranges over all objects [Frege, by Tait]
Frege's domain for variables is all objects, but modern interpretations first fix the domain [Dummett on Frege]
5. Theory of Logic / G. Quantification / 3. Objectual Quantification
Frege introduced quantifiers for generality [Frege, by Weiner]
Frege reduced most quantifiers to 'everything' combined with 'not' [Frege, by McCullogh]
5. Theory of Logic / H. Proof Systems / 1. Proof Systems
Proof theory began with Frege's definition of derivability [Frege, by Prawitz]
5. Theory of Logic / H. Proof Systems / 2. Axiomatic Proof
Frege produced axioms for logic, though that does not now seem the natural basis for logic [Frege, by Kaplan]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / f. Mathematical induction
It may be possible to define induction in terms of the ancestral relation [Frege, by Wright,C]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / b. Type theory
Frege's logic has a hierarchy of object, property, property-of-property etc. [Frege, by Smith,P]
7. Existence / A. Nature of Existence / 1. Nature of Existence
Existence is not a first-order property, but the instantiation of a property [Frege, by Read]
7. Existence / A. Nature of Existence / 3. Being / d. Non-being
A thing which makes no difference seems unlikely to exist [Le Poidevin]
14. Science / D. Explanation / 2. Types of Explanation / a. Types of explanation
In addition to causal explanations, they can also be inferential, or definitional, or purposive [Le Poidevin]
19. Language / C. Assigning Meanings / 4. Compositionality
Frege's account was top-down and decompositional, not bottom-up and compositional [Frege, by Potter]
19. Language / C. Assigning Meanings / 9. Indexical Semantics
We don't just describe a time as 'now' from a private viewpoint, but as a fact about the world [Le Poidevin]
23. Ethics / C. Virtue Theory / 3. Virtues / d. Courage
Being unafraid (perhaps through ignorance) and being brave are two different things [Plato]
26. Natural Theory / C. Causation / 1. Causation
The logical properties of causation are asymmetry, transitivity and irreflexivity [Le Poidevin]
27. Natural Reality / C. Space / 3. Points in Space
We can identify unoccupied points in space, so they must exist [Le Poidevin]
If spatial points exist, then they must be stationary, by definition [Le Poidevin]
27. Natural Reality / C. Space / 4. Substantival Space
Absolute space explains actual and potential positions, and geometrical truths [Le Poidevin]
27. Natural Reality / C. Space / 5. Relational Space
For relationists moving an object beyond the edge of space creates new space [Le Poidevin]
27. Natural Reality / C. Space / 6. Space-Time
We distinguish time from space, because it passes, and it has a unique present moment [Le Poidevin]
27. Natural Reality / D. Time / 1. Nature of Time / e. Eventless time
Since nothing occurs in a temporal vacuum, there is no way to measure its length [Le Poidevin]
Temporal vacuums would be unexperienced, unmeasured, and unending [Le Poidevin]
27. Natural Reality / D. Time / 2. Passage of Time / b. Rate of time
Time can't speed up or slow down, so it doesn't seem to be a 'process' [Le Poidevin]
27. Natural Reality / D. Time / 2. Passage of Time / f. Tenseless (B) series
To say that the past causes the present needs them both to be equally real [Le Poidevin]
The B-series doesn't seem to allow change [Le Poidevin]
If the B-universe is eternal, why am I trapped in a changing moment of it? [Le Poidevin]
27. Natural Reality / D. Time / 2. Passage of Time / g. Time's arrow
Time's arrow is not causal if there is no temporal gap between cause and effect [Le Poidevin]
An ordered series can be undirected, but time favours moving from earlier to later [Le Poidevin]
If time's arrow is causal, how can there be non-simultaneous events that are causally unconnected? [Le Poidevin]
If time's arrow is psychological then different minds can impose different orders on events [Le Poidevin]
There are Thermodynamic, Psychological and Causal arrows of time [Le Poidevin]
Presumably if time's arrow is thermodynamic then time ends when entropy is complete [Le Poidevin]
If time is thermodynamic then entropy is necessary - but the theory says it is probable [Le Poidevin]
27. Natural Reality / D. Time / 2. Passage of Time / i. Time and motion
Instantaneous motion is an intrinsic disposition to be elsewhere [Le Poidevin]
The dynamic view of motion says it is primitive, and not reducible to objects, properties and times [Le Poidevin]
27. Natural Reality / D. Time / 2. Passage of Time / k. Temporal truths
If the present could have diverse pasts, then past truths can't have present truthmakers [Le Poidevin]
27. Natural Reality / D. Time / 3. Parts of Time / a. Beginning of time
The present is the past/future boundary, so the first moment of time was not present [Le Poidevin]
27. Natural Reality / D. Time / 3. Parts of Time / c. Intervals
The primitive parts of time are intervals, not instants [Le Poidevin]
27. Natural Reality / D. Time / 3. Parts of Time / e. Present moment
If time is infinitely divisible, then the present must be infinitely short [Le Poidevin]
27. Natural Reality / E. Cosmology / 10. Multiverse
The multiverse is distinct time-series, as well as spaces [Le Poidevin]
28. God / A. Divine Nature / 5. God and Time
How could a timeless God know what time it is? So could God be both timeless and omniscient? [Le Poidevin]
28. God / B. Proving God / 2. Proofs of Reason / b. Ontological Proof critique
The predicate 'exists' is actually a natural language expression for a quantifier [Frege, by Weiner]