Combining Texts

All the ideas for 'teaching', 'Thought and Reality' and 'Parts of Classes'

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67 ideas

1. Philosophy / A. Wisdom / 1. Nature of Wisdom
Speak the truth, for this alone deifies man [Pythagoras, by Porphyry]
1. Philosophy / B. History of Ideas / 2. Ancient Thought
Pythagoras discovered the numerical relation of sounds on a string [Pythagoras, by Diog. Laertius]
3. Truth / F. Semantic Truth / 2. Semantic Truth
Truth is part of semantics, since valid inference preserves truth [Dummett]
4. Formal Logic / F. Set Theory ST / 1. Set Theory
Sets are mereological sums of the singletons of their members [Lewis, by Armstrong]
We can build set theory on singletons: classes are then fusions of subclasses, membership is the singleton [Lewis]
4. Formal Logic / F. Set Theory ST / 2. Mechanics of Set Theory / b. Terminology of ST
Classes divide into subclasses in many ways, but into members in only one way [Lewis]
A subclass of a subclass is itself a subclass; a member of a member is not in general a member [Lewis]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set
We needn't accept this speck of nothingness, this black hole in the fabric of Reality! [Lewis]
We can accept the null set, but there is no null class of anything [Lewis]
There are four main reasons for asserting that there is an empty set [Lewis]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / c. Unit (Singleton) Sets
If we don't understand the singleton, then we don't understand classes [Lewis]
We can replace the membership relation with the member-singleton relation (plus mereology) [Lewis]
If singleton membership is external, why is an object a member of one rather than another? [Lewis]
Maybe singletons have a structure, of a thing and a lasso? [Lewis]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
Set theory has some unofficial axioms, generalisations about how to understand it [Lewis]
Set theory reduces to a mereological theory with singletons as the only atoms [Lewis, by MacBride]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / a. Sets as existing
If singletons are where their members are, then so are all sets [Lewis]
A huge part of Reality is only accepted as existing if you have accepted set theory [Lewis]
Set theory isn't innocent; it generates infinities from a single thing; but mathematics needs it [Lewis]
5. Theory of Logic / D. Assumptions for Logic / 1. Bivalence
Language can violate bivalence because of non-referring terms or ill-defined predicates [Dummett]
5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle
The law of excluded middle is the logical reflection of the principle of bivalence [Dummett]
5. Theory of Logic / G. Quantification / 6. Plural Quantification
Plural quantification lacks a complete axiom system [Lewis]
I like plural quantification, but am not convinced of its connection with second-order logic [Lewis]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / m. One
For Pythagoreans 'one' is not a number, but the foundation of numbers [Pythagoras, by Watson]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / f. Zermelo numbers
Zermelo's model of arithmetic is distinctive because it rests on a primitive of set theory [Lewis]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
Giving up classes means giving up successful mathematics because of dubious philosophy [Lewis]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / a. Structuralism
To be a structuralist, you quantify over relations [Lewis]
7. Existence / A. Nature of Existence / 2. Types of Existence
Existence doesn't come in degrees; once asserted, it can't then be qualified [Lewis]
7. Existence / C. Structure of Existence / 8. Stuff / a. Pure stuff
We have no idea of a third sort of thing, that isn't an individual, a class, or their mixture [Lewis]
Atomless gunk is an individual whose parts all have further proper parts [Lewis]
7. Existence / D. Theories of Reality / 2. Realism
Philosophers should not presume reality, but only invoke it when language requires it [Dummett]
7. Existence / D. Theories of Reality / 4. Anti-realism
We can't make sense of a world not apprehended by a mind [Dummett]
7. Existence / D. Theories of Reality / 8. Facts / b. Types of fact
Since 'no bird here' and 'no squirrel here' seem the same, we must talk of 'atomic' facts [Dummett]
7. Existence / D. Theories of Reality / 8. Facts / c. Facts and truths
We know we can state facts, with true statements [Dummett]
7. Existence / D. Theories of Reality / 10. Vagueness / d. Vagueness as linguistic
'That is red or orange' might be considered true, even though 'that is red' and 'that is orange' were not [Dummett]
8. Modes of Existence / B. Properties / 11. Properties as Sets
A property is any class of possibilia [Lewis]
9. Objects / C. Structure of Objects / 5. Composition of an Object
The many are many and the one is one, so they can't be identical [Lewis]
Lewis affirms 'composition as identity' - that an object is no more than its parts [Lewis, by Merricks]
9. Objects / C. Structure of Objects / 8. Parts of Objects / b. Sums of parts
In mereology no two things consist of the same atoms [Lewis]
Trout-turkeys exist, despite lacking cohesion, natural joints and united causal power [Lewis]
Given cats, a fusion of cats adds nothing further to reality [Lewis]
The one has different truths from the many; it is one rather than many, one rather than six [Lewis]
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
Lewis only uses fusions to create unities, but fusions notoriously flatten our distinctions [Oliver/Smiley on Lewis]
A commitment to cat-fusions is not a further commitment; it is them and they are it [Lewis]
Lewis prefers giving up singletons to giving up sums [Lewis, by Fine,K]
12. Knowledge Sources / B. Perception / 2. Qualities in Perception / a. Qualities in perception
Some say qualities are parts of things - as repeatable universals, or as particulars [Lewis]
12. Knowledge Sources / D. Empiricism / 5. Empiricism Critique
Empirical and a priori knowledge are not distinct, but are extremes of a sliding scale [Dummett]
18. Thought / A. Modes of Thought / 1. Thought
A theory of thought will include propositional attitudes as well as propositions [Dummett]
The theories of meaning and understanding are the only routes to an account of thought [Dummett]
18. Thought / E. Abstraction / 8. Abstractionism Critique
To 'abstract from' is a logical process, as opposed to the old mental view [Dummett]
19. Language / A. Nature of Meaning / 4. Meaning as Truth-Conditions
To know the truth-conditions of a sentence, you must already know the meaning [Dummett]
19. Language / A. Nature of Meaning / 5. Meaning as Verification
A justificationist theory of meaning leads to the rejection of classical logic [Dummett]
Verificationism could be realist, if we imagined the verification by a superhuman power [Dummett]
If truths about the past depend on memories and current evidence, the past will change [Dummett]
19. Language / A. Nature of Meaning / 6. Meaning as Use
We could only guess the meanings of 'true' and 'false' when sentences were used [Dummett]
19. Language / A. Nature of Meaning / 7. Meaning Holism / a. Sentence meaning
Sentences are the primary semantic units, because they can say something [Dummett]
19. Language / D. Propositions / 1. Propositions
We can't distinguish a proposition from its content [Dummett]
22. Metaethics / B. Value / 2. Values / d. Health
Pythagoras taught that virtue is harmony, and health, and universal good, and God [Pythagoras, by Diog. Laertius]
23. Ethics / C. Virtue Theory / 3. Virtues / c. Justice
For Pythagoreans, justice is simply treating all people the same [Pythagoras, by Aristotle]
26. Natural Theory / A. Speculations on Nature / 4. Mathematical Nature
When musical harmony and rhythm were discovered, similar features were seen in bodily movement [Pythagoras, by Plato]
Pythagoreans define timeliness, justice and marriage in terms of numbers [Pythagoras, by Aristotle]
Pythagoreans think mathematical principles are the principles of all of nature [Pythagoras, by Aristotle]
Pythagoreans say things imitate numbers, but Plato says things participate in numbers [Pythagoras, by Aristotle]
For Pythagoreans the entire universe is made of numbers [Pythagoras, by Aristotle]
27. Natural Reality / D. Time / 1. Nature of Time / d. Time as measure
Time is the measure of change, so we can't speak of time before all change [Dummett]
27. Natural Reality / D. Time / 1. Nature of Time / h. Presentism
If Presentism is correct, we cannot even say that the present changes [Dummett]
29. Religion / D. Religious Issues / 2. Immortality / a. Immortality
The modern idea of an immortal soul was largely created by Pythagoras [Pythagoras, by Watson]