Combining Texts

All the ideas for 'Frege's Theory of Numbers', 'Parerga and Paralipomena' and 'Ontology and Mathematical Truth'

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33 ideas

1. Philosophy / E. Nature of Metaphysics / 5. Metaphysics beyond Science
Metaphysics studies the inexplicable ends of explanation [Schopenhauer]
     Full Idea: The plummet touches the bottom of the sea now at a greater depth, now at a less, but is bound to reach it somewhere sooner or later; the study of this inexplicable devolves upon metaphysics.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], I:1)
     A reaction: This definition of metapysics contains the germ of despair about the subject. Does he hope that metaphysicians can explain what nobody else can?
4. Formal Logic / F. Set Theory ST / 1. Set Theory
'Impure' sets have a concrete member, while 'pure' (abstract) sets do not [Jubien]
     Full Idea: Any set with a concrete member is 'impure'. 'Pure' sets are those that are not impure, and are paradigm cases of abstract entities, such as the sort of sets apparently dealt with in Zermelo-Fraenkel (ZF) set theory.
     From: Michael Jubien (Ontology and Mathematical Truth [1977], p.116)
     A reaction: [I am unclear whether Jubien is introducing this distinction] This seems crucial in accounts of mathematics. On the one had arithmetic can be built from Millian pebbles, giving impure sets, while logicists build it from pure sets.
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A model is 'fundamental' if it contains only concrete entities [Jubien]
     Full Idea: A first-order model can be viewed as a kind of ordered set, and if the domain of the model contains only concrete entities then it is a 'fundamental' model.
     From: Michael Jubien (Ontology and Mathematical Truth [1977], p.117)
     A reaction: An important idea. Fundamental models are where the world of logic connects with the physical world. Any account of relationship between fundamental models and more abstract ones tells us how thought links to world.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / d. Natural numbers
There couldn't just be one number, such as 17 [Jubien]
     Full Idea: It makes no sense to suppose there might be just one natural number, say seventeen.
     From: Michael Jubien (Ontology and Mathematical Truth [1977], p.113)
     A reaction: Hm. Not convinced. If numbers are essentially patterns, we might only have the number 'twelve', because we had built our religion around anything which exhibited that form (in any of its various arrangements). Nice point, though.
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / c. Counting procedure
Parsons says counting is tagging as first, second, third..., and converting the last to a cardinal [Parsons,C, by Heck]
     Full Idea: In Parsons's demonstrative model of counting, '1' means the first, and counting says 'the first, the second, the third', where one is supposed to 'tag' each object exactly once, and report how many by converting the last ordinal into a cardinal.
     From: report of Charles Parsons (Frege's Theory of Numbers [1965]) by Richard G. Heck - Cardinality, Counting and Equinumerosity 3
     A reaction: This sounds good. Counting seems to rely on that fact that numbers can be both ordinals and cardinals. You don't 'convert' at the end, though, because all the way you mean 'this cardinality in this order'.
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / a. Structuralism
The subject-matter of (pure) mathematics is abstract structure [Jubien]
     Full Idea: The subject-matter of (pure) mathematics is abstract structure per se.
     From: Michael Jubien (Ontology and Mathematical Truth [1977], p.115)
     A reaction: This is the Structuralist idea beginning to take shape after Benacerraf's launching of it. Note that Jubien gets there by his rejection of platonism, whereas some structuralist have given a platonist interpretation of structure.
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / b. Against mathematical platonism
If we all intuited mathematical objects, platonism would be agreed [Jubien]
     Full Idea: If the intuition of mathematical objects were general, there would be no real debate over platonism.
     From: Michael Jubien (Ontology and Mathematical Truth [1977], p.111)
     A reaction: It is particularly perplexing when Gödel says that his perception of them is just like sight or smell, since I have no such perception. How do you individuate very large numbers, or irrational numbers, apart from writing down numerals?
How can pure abstract entities give models to serve as interpretations? [Jubien]
     Full Idea: I am unable to see how the mere existence of pure abstract entities enables us to concoct appropriate models to serve as interpretations.
     From: Michael Jubien (Ontology and Mathematical Truth [1977], p.111)
     A reaction: Nice question. It is always assumed that once we have platonic realm, that everything else follows. Even if we are able to grasp the objects, despite their causal inertness, we still have to discern innumerable relations between them.
Since mathematical objects are essentially relational, they can't be picked out on their own [Jubien]
     Full Idea: The essential properties of mathematical entities seem to be relational, ...so we make no progress unless we can pick out some mathematical entities wihout presupposing other entities already picked out.
     From: Michael Jubien (Ontology and Mathematical Truth [1977], p.112)
     A reaction: [compressed] Jubien is a good critic of platonism. He has identified the problem with Frege's metaphor of a 'borehole', where we discover delightful new properties of numbers simply by reaching them.
7. Existence / D. Theories of Reality / 2. Realism
For me the objective thing-in-itself is the will [Schopenhauer]
     Full Idea: Thing in itself signifies that which exists independently of our perception, that which actually is; …to Kant it was '= x'; to me it is will.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], IV:61)
     A reaction: Does he mean his own will, which is plausible since he has direct experience of it, or is he referring will in general - whatever that is?
9. Objects / A. Existence of Objects / 2. Abstract Objects / c. Modern abstracta
The empty set is the purest abstract object [Jubien]
     Full Idea: The empty set is the pure abstract object par excellence.
     From: Michael Jubien (Ontology and Mathematical Truth [1977], p.118 n8)
     A reaction: So a really good PhD on the empty set could crack the whole nature of reality. Get to work, whoever you are!
11. Knowledge Aims / A. Knowledge / 3. Value of Knowledge
Knowledge is not power! Ignorant people possess supreme authority [Schopenhauer]
     Full Idea: Knowledge is power. The devil it is! One man can have a great deal of knowledge without its giving him the least power, while another possesses supreme authority but next to no knowledge.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], III:43)
     A reaction: He is referring to Bacon's famous adage. Bacon may be right about military affairs, but not about politics.
12. Knowledge Sources / A. A Priori Knowledge / 1. Nature of the A Priori
A priori propositions are those we could never be seriously motivated to challenge [Schopenhauer]
     Full Idea: A dictate of reason is the name we give to certain propositions which we hold to be true without investigation, and of which we think ourselves so firmly convinced we should be incapable of seriously testing them even if we wanted to.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], I:12)
     A reaction: This is closer to the cautious way modern thinkers are inclined to express the idea. Even Quine would be reasonably happy with this.
14. Science / D. Explanation / 1. Explanation / a. Explanation
All knowledge and explanation rests on the inexplicable [Schopenhauer]
     Full Idea: The fundament upon which all our knowledge and learning rests is the inexplicable. It is to this that every explanation, through few or many intermediary stages, leads.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], I:1)
     A reaction: This is obviously true, and the only question is whether it is a necessary or a contingent truth.
15. Nature of Minds / B. Features of Minds / 2. Unconscious Mind
Half our thinking is unconscious, and we reach conclusions while unaware of premises [Schopenhauer]
     Full Idea: One might almost believe that half our thinking takes place unconsciously.. Usually we arrive at a conclusion without having clearly thought about the premises which lead to it.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], III:40)
     A reaction: Schopenhauer was a major pioneer of this crucial idea. I'm beginning to think it is much greater than a half.
16. Persons / F. Free Will / 6. Determinism / a. Determinism
We don't control our own thinking [Schopenhauer]
     Full Idea: Thoughts come not when we want but when they want.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], III:37)
     A reaction: One of my favourite Nietzsche ideas originated in Schopenhauer!
18. Thought / D. Concepts / 2. Origin of Concepts / b. Empirical concepts
All of our concepts are borrowed from perceptual knowledge [Schopenhauer]
     Full Idea: The entire property of a concept consists in nothing more than what has been begged and borrowed from perceptual knowledge, which is the true and inexhaustible source of all insight.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], I:9)
     A reaction: Schopenhauer is usually seen as a sort of idealist, but this is a full endorsement of the empirical view of concepts, to which I largely subscribe. Note that he talks of 'knowledge', rather than of 'experience'.
21. Aesthetics / A. Aesthetic Experience / 1. Aesthetics
Aesthetics concerns how we can take pleasure in an object, with no reference to the will [Schopenhauer]
     Full Idea: The central problem of aesthetics is how satisfaction with and pleasure in an object are possible without any reference thereof to our willing.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], II:415), quoted by Christopher Janaway - Schopenhauer 6 'Aesthetic'
     A reaction: This does seem a good distinction. We can divide pleasures into willed and unwilled. Compare thinking that some remote stranger (in a photograph) is very beautiful, with falling in love with someone.
21. Aesthetics / A. Aesthetic Experience / 4. Beauty
The beautiful is a perception of Plato's Forms, which eliminates the will [Schopenhauer]
     Full Idea: In the beautiful we always perceive the intrinsic and primary form of animate and inanimate nature, that is to say Plato's Ideas thereof. …When an aesthetic perception occurs the will completely vanishes from consciousness.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], XIX:205)
     A reaction: An essential Schopenauer idea. Iris Murdoch said something similar.
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / e. Human nature
Man is essentially a dreadful wild animal [Schopenhauer]
     Full Idea: Man is at bottom a dreadful wild animal.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], VIII:114)
     A reaction: As an example he cites the slave owners in the United States.
22. Metaethics / C. The Good / 3. Pleasure / c. Value of pleasure
Pleasure is weaker, and pain stronger, than we expect [Schopenhauer]
     Full Idea: As a rule we find pleasure much less pleasurable, pain much more painful than we expected.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], XII:149)
     A reaction: Never go on holiday with Schopenhauer. This is more accurate about pain, I think.
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / e. Character
A man's character can be learned from a single characteristic action [Schopenhauer]
     Full Idea: As a botanist can recognise the whole plant from one leaf, …so an accurate knowledge of a man's character can be arrived at from a single characteristic action.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], VIII:118)
     A reaction: Very true. Great novelists specialise in such observations. One word can reveal a character, as well as one action.
23. Ethics / C. Virtue Theory / 3. Virtues / a. Virtues
The five Chinese virtues: pity, justice, politeness, wisdom, honesty [Schopenhauer]
     Full Idea: The Chinese name five cardinal virtues: pity, justice, politeness, wisdom and honesty.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], VIII:110)
     A reaction: I like politeness being on the list, though it seems rather superficial to be a virtue of character. Respect would be better.
Buddhists wisely start with the cardinal vices [Schopenhauer]
     Full Idea: Because of their profounder ethical and metaphysical insight, the Buddhists start not with the cardinal virtues but with cardinal vices, …which are lust, sloth, wrath and avarice (and maybe hatred).
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], VIII:110)
     A reaction: This may be right. Our lives are affected much more by the vices of others than by their virtues, and most virtuous behaviour aims at rectifying the bad effects of other people's vices.
23. Ethics / F. Existentialism / 4. Boredom
Boredom is only felt by those clever enough to need activity [Schopenhauer]
     Full Idea: Only in the cleverest animals such as dogs and apes does the need for activity, and with that boredom, make itself felt.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], III:50)
     A reaction: But it is much more frequently young creatures, of almost any kind, that seek constant activity, and get continually restless. The most active adults need not be the cleverest.
Human life is a mistake, shown by boredom, which is direct awareness of the fact [Schopenhauer]
     Full Idea: Human life must be some kind of mistake. ...Boredom is a direct proof that existence is in itself valueless, for boredom is nothing other than the sensation of the emptiness of existence.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], XI:146)
     A reaction: I think it is a good advertisement for existentialism that it makes something more out of boredom than Schopenhauer does.
24. Political Theory / B. Nature of a State / 1. Purpose of a State
The state only exists to defend citizens, from exterior threats, and from one another [Schopenhauer]
     Full Idea: The state is essentially no more than an institution for the protection of the whole against attacks from without, and the protection of its individual members from attacks by one another.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], IX:123)
     A reaction: He then has a swipe at Hegel for his inflated idea of the importance of the state. Schopenhauer is close to Hobbes on this one.
25. Social Practice / A. Freedoms / 1. Slavery
Poverty and slavery are virtually two words for the same thing [Schopenhauer]
     Full Idea: Poverty and slavery are only two forms - on might almost say two words for - the same thing, the essence of which is that a man's energies are expended for the most part not on his own behalf but on that of others.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], IX:125)
     A reaction: The modern world is full of people who righteously despise slavery, but think only of the poor that it serves them right.
25. Social Practice / A. Freedoms / 3. Free speech
The freedom of the press to sell poison outweighs its usefulness [Schopenhauer]
     Full Idea: Freedom of the press must be regarded as a permit to sell poison. …I very much fear, therefore, that the dangers of press freedom outweigh its usefulness.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], IX:127)
     A reaction: On the whole the modern world disagrees with this view, but watching the popular press in Britain in the last twenty years has made me sympathise with Schopenhauer.
25. Social Practice / F. Life Issues / 4. Suicide
If suicide was quick and easy, most people would have done it by now [Schopenhauer]
     Full Idea: Perhaps there is no one alive who would not already have put an end to his life if this end were something purely negative, a sudden cessation of existence.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], XIII:158)
     A reaction: Nonsense, on the whole, but it is a nice question how many people would do it if it only took a painless instant.
25. Social Practice / F. Life Issues / 5. Sexual Morality
Would humanity still exist if sex wasn't both desired and pleasurable? [Schopenhauer]
     Full Idea: If the act of procreation were neither the outcome of a desire nor accompanied by feelings of pleasure, but a matter to be decided on the basis of purely rational considerations, is it likely the human race would still exist?
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], XII:156)
     A reaction: This is almost certainly correct in the modern world. In tougher economic circumstances people seem desperate to have children who will help them survive.
29. Religion / D. Religious Issues / 1. Religious Commitment / a. Religious Belief
Only religion introduces serious issues to uneducated people [Schopenhauer]
     Full Idea: Religion is the only means of introducing some notion of the high significance of life into the uncultivated heads of the masses.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], XV:174)
     A reaction: Cf Philip Larkin's poem 'Church Going'. On the whole Schopenhauer didn't actually believe that our lives had any 'high significance'.
29. Religion / D. Religious Issues / 3. Problem of Evil / a. Problem of Evil
The Creator created the possibilities for worlds, so should have made a better one than this possible [Schopenhauer]
     Full Idea: The Creator created not only the world, but also created possibility itself; therefore he should have created the possibility of a better world than this one.
     From: Arthur Schopenhauer (Parerga and Paralipomena [1851], XII:156)
     A reaction: This is explicitly a response to Leibniz's claim that the Creator selected the best of all possible worlds from the available options. The Euthyphro Question hovers here: must the Creator accept what is possible (the platonic view), or create possibility?