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All the ideas for 'The philosophical basis of intuitionist logic', 'Philebus' and 'Parts of Classes'

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65 ideas

4. Formal Logic / E. Nonclassical Logics / 2. Intuitionist Logic
Dummett says classical logic rests on meaning as truth, while intuitionist logic rests on assertability [Dummett, by Kitcher]
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]
4. Formal Logic / G. Formal Mereology / 1. Mereology
It seems absurd that seeing a person's limbs, the one is many, and yet the many are one [Plato]
5. Theory of Logic / G. Quantification / 1. Quantification
Classical quantification is an infinite conjunction or disjunction - but you may not know all the instances [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 / 2. Geometry
It is absurd to define a circle, but not be able to recognise a real one [Plato]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / f. Arithmetic
Daily arithmetic counts unequal things, but pure arithmetic equalises them [Plato]
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 / C. Structure of Existence / 8. Stuff / b. Mixtures
If a mixture does not contain measure and proportion, it is corrupted and destroyed [Plato]
Any mixture which lacks measure and proportion doesn't even count as a mixture at all [Plato]
8. Modes of Existence / B. Properties / 11. Properties as Sets
A property is any class of possibilia [Lewis]
8. Modes of Existence / D. Universals / 6. Platonic Forms / b. Partaking
If the good is one, is it unchanged when it is in particulars, and is it then separated from itself? [Plato]
9. Objects / B. Unity of Objects / 1. Unifying an Object / c. Unity as conceptual
A thing can become one or many, depending on how we talk about it [Plato]
9. Objects / C. Structure of Objects / 5. Composition of an Object
If one object is divided into its parts, someone can then say that one are many and many is one [Plato]
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]
11. Knowledge Aims / B. Certain Knowledge / 1. Certainty
How can you be certain about aspects of the world if they aren't constant? [Plato]
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]
19. Language / A. Nature of Meaning / 4. Meaning as Truth-Conditions
Stating a sentence's truth-conditions is just paraphrasing the sentence [Dummett]
If a sentence is effectively undecidable, we can never know its truth conditions [Dummett]
19. Language / A. Nature of Meaning / 6. Meaning as Use
Meaning as use puts use beyond criticism, and needs a holistic view of language [Dummett]
21. Aesthetics / A. Aesthetic Experience / 4. Beauty
If goodness involves moderation and proportion, then it seems to be found in beauty [Plato]
22. Metaethics / C. The Good / 1. Goodness / a. Form of the Good
The good involves beauty, proportion and truth [Plato]
Neither intellect nor pleasure are the good, because they are not perfect and self-sufficient [Plato]
22. Metaethics / C. The Good / 1. Goodness / b. Types of good
Good first, then beauty, then reason, then knowledge, then pleasure [Plato, by PG]
22. Metaethics / C. The Good / 3. Pleasure / a. Nature of pleasure
Some of the pleasures and pains we feel are false [Plato]
22. Metaethics / C. The Good / 3. Pleasure / b. Types of pleasure
A small pure pleasure is much finer than a large one contaminated with pain [Plato]
22. Metaethics / C. The Good / 3. Pleasure / c. Value of pleasure
Pleasure is certainly very pleasant, but it doesn't follow that all pleasures are good [Plato]
The good must be sufficient and perfect, and neither intellect nor pleasure are that [Plato]
Reason, memory, truth and wisdom are far better than pleasure, for those who can attain them [Plato]
Would you prefer a life of pleasure without reason, or one of reason without pleasure? [Plato]
It is unlikely that the gods feel either pleasure or pain [Plato]
22. Metaethics / C. The Good / 3. Pleasure / d. Sources of pleasure
We feel pleasure when we approach our natural state of harmony [Plato]
22. Metaethics / C. The Good / 3. Pleasure / e. Role of pleasure
Intense pleasure and pain are not felt in a good body, but in a worthless one [Plato]
23. Ethics / A. Egoism / 2. Hedonism
Hedonists must say that someone in pain is bad, even if they are virtuous [Plato]
If you lived a life of maximum pleasure, would you still be lacking anything? [Plato]
A life of pure pleasure with no intellect is the life of a jellyfish [Plato]