Combining Texts

All the ideas for 'The Nature of Things', 'Frege versus Cantor and Dedekind' and 'On the Nature of the Gods ('De natura deorum')'

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34 ideas

1. Philosophy / F. Analytic Philosophy / 7. Limitations of Analysis
Analytic philosophy focuses too much on forms of expression, instead of what is actually said [Tait]
     Full Idea: The tendency to attack forms of expression rather than attempting to appreciate what is actually being said is one of the more unfortunate habits that analytic philosophy inherited from Frege.
     From: William W. Tait (Frege versus Cantor and Dedekind [1996], IV)
     A reaction: The key to this, I say, is to acknowledge the existence of propositions (in brains). For example, this belief will make teachers more sympathetic to pupils who are struggling to express an idea, and verbal nit-picking becomes totally irrelevant.
2. Reason / F. Fallacies / 5. Fallacy of Composition
If the parts of the universe are subject to the law of nature, the whole universe must also be subject to it [Cicero]
     Full Idea: If the parts of the universe are subject to the law of nature, then the universe itself must be subject to this law.
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], II.86)
4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set
The null set was doubted, because numbering seemed to require 'units' [Tait]
     Full Idea: The conception that what can be numbered is some object (including flocks of sheep) relative to a partition - a choice of unit - survived even in the late nineteenth century in the form of the rejection of the null set (and difficulties with unit sets).
     From: William W. Tait (Frege versus Cantor and Dedekind [1996], IX)
     A reaction: This old view can't be entirely wrong! Frege makes the point that if asked to count a pack of cards, you must decide whether to count cards, or suits, or pips. You may not need a 'unit', but you need a concept. 'Units' name concept-extensions nicely!
4. Formal Logic / F. Set Theory ST / 7. Natural Sets
A class is natural when everybody can spot further members of it [Quinton]
     Full Idea: To say that a class is natural is to say that when some of its members are shown to people they pick out others without hesitation and in agreement.
     From: Anthony Quinton (The Nature of Things [1973], 9 'Nat')
     A reaction: He concedes a number of problems with his view, but I admire his attempt to at least begin to distinguish the natural (real!) classes from the ersatz ones. A mention of causal powers would greatly improve his story.
We can have a series with identical members [Tait]
     Full Idea: Why can't we have a series (as opposed to a linearly ordered set) all of whose members are identical, such as (a, a, a...,a)?
     From: William W. Tait (Frege versus Cantor and Dedekind [1996], VII)
     A reaction: The question is whether the items order themselves, which presumably the natural numbers are supposed to do, or whether we impose the order (and length) of the series. What decides how many a's there are? Do we order, or does nature?
7. Existence / E. Categories / 5. Category Anti-Realism
Extreme nominalists say all classification is arbitrary convention [Quinton]
     Full Idea: Pure, extreme nominalism sees all classification as the product of arbitrary convention.
     From: Anthony Quinton (The Nature of Things [1973], 9 'Nat')
     A reaction: I'm not sure what the word 'arbitrary' is doing there. Nominalists are not daft, and if they can classify any way they like, they are not likely to choose an 'arbitrary' system. Pragmatism tells the right story here.
8. Modes of Existence / B. Properties / 5. Natural Properties
The naturalness of a class depends as much on the observers as on the objects [Quinton]
     Full Idea: The naturalness of a class depends as essentially on the nature of the observers who classify as it does on the nature of the objects that they classify. ...It depends on our perceptual apparatus, and on our relatively mutable needs and interests.
     From: Anthony Quinton (The Nature of Things [1973], 9 'Nat')
     A reaction: This seems to translate 'natural' as 'natural for us', which is not much use to scientists, who spend quite a lot of effort combating folk wisdom. Do desirable sports cars constitute a natural class?
Properties imply natural classes which can be picked out by everybody [Quinton]
     Full Idea: To say there are properties is to say there are natural classes, classes introduction to some of whose members enables people to pick out others without hesitation and in agreement.
     From: Anthony Quinton (The Nature of Things [1973], 9 'Nat')
     A reaction: Aristotle would like this approach, but it doesn't find many friends among modern logician/philosophers. We should go on to ask why people agree on these things. Causal powers will then come into it.
8. Modes of Existence / D. Universals / 4. Uninstantiated Universals
Uninstantiated properties must be defined using the instantiated ones [Quinton]
     Full Idea: Properties that have no concrete instances must be defined in terms of those that have.
     From: Anthony Quinton (The Nature of Things [1973], 9 'Nat')
     A reaction: I wonder what the dodo used to smell like?
9. Objects / A. Existence of Objects / 5. Individuation / b. Individuation by properties
An individual is a union of a group of qualities and a position [Quinton, by Campbell,K]
     Full Idea: Quinton proposes that an individual is a union of a group of qualities and a position.
     From: report of Anthony Quinton (The Nature of Things [1973], Pt I) by Keith Campbell - The Metaphysic of Abstract Particulars §5
     A reaction: This seems the obvious defence of a bundle account of objects against the charge that indiscernibles would have to be identical. It introduces, however, 'positions' into the ontology, but maybe that price must be paid. Materialism needs space.
17. Mind and Body / A. Mind-Body Dualism / 8. Dualism of Mind Critique
Why would mind mix with matter if it didn't need it? [Cicero]
     Full Idea: If the gods have no need of the sensible world, why mix up mind with water and water with mind, if mind can exist by itself without any need of matter?
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], I.24)
     A reaction: This question migrates into our puzzles about why a separate mental substance would be produced by evolution. If it is device physical systems use to promote themselves, mental substance is reduced to an inferior and dependent role.
18. Thought / E. Abstraction / 2. Abstracta by Selection
Abstraction is 'logical' if the sense and truth of the abstraction depend on the concrete [Tait]
     Full Idea: If the sense of a proposition about the abstract domain is given in terms of the corresponding proposition about the (relatively) concrete domain, ..and the truth of the former is founded upon the truth of the latter, then this is 'logical abstraction'.
     From: William W. Tait (Frege versus Cantor and Dedekind [1996], V)
     A reaction: The 'relatively' in parentheses allows us to apply his idea to levels of abstraction, and not just to the simple jump up from the concrete. I think Tait's proposal is excellent, rather than purloining 'abstraction' for an internal concept within logic.
Cantor and Dedekind use abstraction to fix grammar and objects, not to carry out proofs [Tait]
     Full Idea: Although (in Cantor and Dedekind) abstraction does not (as has often been observed) play any role in their proofs, but it does play a role, in that it fixes the grammar, the domain of meaningful propositions, and so determining the objects in the proofs.
     From: William W. Tait (Frege versus Cantor and Dedekind [1996], V)
     A reaction: [compressed] This is part of a defence of abstractionism in Cantor and Dedekind (see K.Fine also on the subject). To know the members of a set, or size of a domain, you need to know the process or function which created the set.
18. Thought / E. Abstraction / 7. Abstracta by Equivalence
Abstraction may concern the individuation of the set itself, not its elements [Tait]
     Full Idea: A different reading of abstraction is that it concerns, not the individuating properties of the elements relative to one another, but rather the individuating properties of the set itself, for example the concept of what is its extension.
     From: William W. Tait (Frege versus Cantor and Dedekind [1996], VIII)
     A reaction: If the set was 'objects in the room next door', we would not be able to abstract from the objects, but we might get to the idea of things being contain in things, or the concept of an object, or a room. Wrong. That's because they are objects... Hm.
18. Thought / E. Abstraction / 8. Abstractionism Critique
Why should abstraction from two equipollent sets lead to the same set of 'pure units'? [Tait]
     Full Idea: Why should abstraction from two equipollent sets lead to the same set of 'pure units'?
     From: William W. Tait (Frege versus Cantor and Dedekind [1996])
     A reaction: [Tait is criticising Cantor] This expresses rather better than Frege or Dummett the central problem with the abstractionist view of how numbers are derived from matching groups of objects.
If abstraction produces power sets, their identity should imply identity of the originals [Tait]
     Full Idea: If the power |A| is obtained by abstraction from set A, then if A is equipollent to set B, then |A| = |B|. But this does not imply that A = B. So |A| cannot just be A, taken in abstraction, unless that can identify distinct sets, ..or create new objects.
     From: William W. Tait (Frege versus Cantor and Dedekind [1996], V)
     A reaction: An elegant piece of argument, which shows rather crucial facts about abstraction. We are then obliged to ask how abstraction can create an object or a set, if the central activity of abstraction is just ignoring certain features.
19. Language / F. Communication / 1. Rhetoric
Eloquence educates, exhorts, comforts, distracts and unites us, and raises us from savagery [Cicero]
     Full Idea: How wonderful is the power of eloquence! It enables us to learn and to teach. We use it to exhort and persuade, to comfort the unfortunate, to distract the timid and calm the passionate. It unites us in law and society, and raises us from savagery.
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], 2.147)
     A reaction: [compressed] Cicero would have been well aware of the doubts about rhetoric felt by Socrates (and possibly Plato). Cicero was probably the greatest Roman orator.
25. Social Practice / D. Justice / 3. Punishment / c. Deterrence of crime
We have the death penalty, but still have thousands of robbers [Cicero]
     Full Idea: We have robbers by the thousand, although they have the penalty of death before their eyes.
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], I.86)
26. Natural Theory / A. Speculations on Nature / 1. Nature
Some regard nature simply as an irrational force that imparts movement [Cicero]
     Full Idea: Some regard nature as an irrational force which merely imparts a mechanical motion to material bodies.
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], II.81)
28. God / A. Divine Nature / 4. Divine Contradictions
Why shouldn't the gods fear their own destruction? [Cicero]
     Full Idea: Why should the gods not be apprehensive of their own possible dissolution?
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], I.114)
28. God / A. Divine Nature / 6. Divine Morality / b. Euthyphro question
I wonder whether loss of reverence for the gods would mean the end of all virtue [Cicero]
     Full Idea: I do not know whether, if our reverence for the gods were lost, we should not also see the end of good faith, of human brotherhood, and even of justice itself, which is the keystone of all the virtues.
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], I.3)
28. God / A. Divine Nature / 6. Divine Morality / d. God decrees morality
God doesn't obey the laws of nature; they are subject to the law of God [Cicero]
     Full Idea: God is not subject to obey the laws of nature. It is nature that is subject to the laws of God.
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], II.77)
28. God / B. Proving God / 2. Proofs of Reason / a. Ontological Proof
It seems clear to me that we have an innate idea of the divine [Cicero]
     Full Idea: Let us take it as agreed that we have a preconception or "an innate idea" (as I have called it) or a prior knowledge of the divine.
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], I.44)
28. God / B. Proving God / 2. Proofs of Reason / b. Ontological Proof critique
Many primitive people know nothing of the gods [Cicero]
     Full Idea: There must be many wild and primitive peoples who have no idea of the gods at all.
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], I.62)
28. God / B. Proving God / 3. Proofs of Evidence / b. Teleological Proof
If the barbarians of Britain saw a complex machine, they would be baffled, but would know it was designed [Cicero]
     Full Idea: If someone were to take the celestial globe of Posidonius and show it to the people of Britain, would a single one of those barbarians fail to see that it was the product of a conscious intelligence?
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], II.88)
Chance is no more likely to create the world than spilling lots of letters is likely to create a famous poem [Cicero]
     Full Idea: If someone thinks chance made the world, he should also think that if an infinite number of the letters of the alphabet were shaken together and poured out on the ground it would be possible for them to spell out the whole 'Annals' of Ennius.
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], II.93)
It is obvious from order that someone is in charge, as when we visit a gymnasium [Cicero]
     Full Idea: If one comes into a gymnasium and sees everything properly arranged and carried on in order, one does not imagine these arrangements to be accidental, but infers that there is someone in command whose orders are obeyed.
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], II.15)
If a person cannot feel the power of God when looking at the stars, they are probably incapable of feeling [Cicero]
     Full Idea: If any man cannot feel the power of God when he looks upon the stars, then I doubt whether he is capable of any feeling at all.
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], II.55)
28. God / B. Proving God / 3. Proofs of Evidence / c. Teleological Proof critique
If everything with regular movement and order is divine, then recurrent illnesses must be divine [Cicero]
     Full Idea: Are we to find a divinity in every regular movement and in everything which happens in a constant order? If so, we shall have to say that tertian and quartan agues are divine because their course and recurrence is absolutely uniform.
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], III.24)
28. God / C. Attitudes to God / 1. Monotheism
Either the gods are identical, or one is more beautiful than another [Cicero]
     Full Idea: Are the gods all exactly the same? If not, then one must be more beautiful than another.
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], I.80)
28. God / C. Attitudes to God / 4. God Reflects Humanity
The gods are happy, so virtuous, so rational, so must have human shape [Cicero]
     Full Idea: We agree the gods are happy, and no happiness is possible without virtue: there is no virtue without reason: and reason is associated only with the human form: then it must follow that the gods themselves have human shape.
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], I.48)
28. God / C. Attitudes to God / 5. Atheism
Why believe in gods if you have never seen them? [Cicero]
     Full Idea: Did you ever actually see a god? Then why do you believe that gods exist?
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], I.88)
29. Religion / D. Religious Issues / 3. Problem of Evil / a. Problem of Evil
The lists of good men who have suffered and bad men who have prospered are endless [Cicero]
     Full Idea: Time would fail me if I tried to list all the good men for whom things have turned out badly. So it would if I tried to mention all the wicked who have prospered.
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], III.80)
29. Religion / D. Religious Issues / 3. Problem of Evil / b. Human Evil
The gods blame men for having vices, but they could have given us enough reason to avoid them [Cicero]
     Full Idea: You gods say that the fault lies in the vices of mankind. But you could have endowed men with reason in a form which would exclude all vice and crime.
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], III.76)