Combining Texts

All the ideas for 'Introduction to 'Language Truth and Logic'', 'Centring' and 'Frege versus Cantor and Dedekind'

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23 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.
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
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 / A. Nature of Existence / 3. Being / h. Dasein (being human)
Being is revealed at the point between waking and sleep [Anon (Cent)]
     Full Idea: At the point of sleep when sleep has not yet come and external wakefulness vanishes, at this point being is revealed.
     From: Anon (Cent) (Centring [c.500 BCE], 50)
     A reaction: One for Heidegger. The problem with eastern philosophy is that no one expects that this revelation could be put into words, so we cannot compare our revelations of being, or pass them on to others. Which means they can't be criticised.
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / c. Empirical foundations
Basic propositions refer to a single experience, are incorrigible, and conclusively verifiable [Ayer]
     Full Idea: There is a class of empirical propositions, which I call 'basic propositions', which can be verified conclusively, since they refer solely to the contents of a single experience, which are incorrigible.
     From: A.J. Ayer (Introduction to 'Language Truth and Logic' [1946], p.13)
     A reaction: A classic statement of empirical foundationalism. I sort of agree that 'single experiences' are a 'given' for philosophy, but is questionable whether there is anything which could both be a single experience AND give rise to a proposition.
15. Nature of Minds / A. Nature of Mind / 4. Other Minds / a. Other minds
Neglect your self, and feel the consciousness of each other being [Anon (Cent)]
     Full Idea: Feel the consciousness of each person as your own consciousness. So, leaving aside concern for self, become each being.
     From: Anon (Cent) (Centring [c.500 BCE], 83)
     A reaction: Good. The western scepticism about other minds puts up a barrier to this sort of thought. The best of Zen is when it encourages the use of imagination to explore what is real. But imagination struggles to distinguish what is true.
15. Nature of Minds / A. Nature of Mind / 4. Other Minds / c. Knowing other minds
The argument from analogy fails, so the best account of other minds is behaviouristic [Ayer]
     Full Idea: There are too many objections to the argument from analogy, so I am inclined to revert to a 'behaviouristic' interpretation of propositions about other people's experiences.
     From: A.J. Ayer (Introduction to 'Language Truth and Logic' [1946], p.26)
     A reaction: It seems odd to vote for behaviourism on one issue, if you aren't a general subscriber. It is one thing to say that behaviour is the best evidence for your explanation, quite another to equate the other mind with its behaviour.
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 / A. Nature of Meaning / 5. Meaning as Verification
A statement is meaningful if observation statements can be deduced from it [Ayer]
     Full Idea: In the improved version, a statement was verifiable, and consequently meaningful, if 'some observation-statement can be deduced from it in conjunction with certain other premises, without being deducible from those other premises alone'.
     From: A.J. Ayer (Introduction to 'Language Truth and Logic' [1946], p.15)
     A reaction: I.Berlin showed that any statement S could pass this test, because if you assert 'S' and 'If S then O', these two statements entail O, which could be some random observation. Hence a 1946 revised version had to be produced.
Directly verifiable statements must entail at least one new observation statement [Ayer]
     Full Idea: A statement is directly verifiable if it is either itself an observation-statement,or is such that in conjunction with one or more observation-statements it entails at least one observation-statement which is not deducible from these other premises alone.
     From: A.J. Ayer (Introduction to 'Language Truth and Logic' [1946], p.17)
     A reaction: This is the 1946 revised version of the Verification Principle, which was then torpedoed by an elaborate counterexample from Alonzo Church. Ayer thereafter abandoned attempts to find a precise statement of it.
The principle of verification is not an empirical hypothesis, but a definition [Ayer]
     Full Idea: I wish the principle of verification to be regarded, not as an empirical hypothesis, but as a definition.
     From: A.J. Ayer (Introduction to 'Language Truth and Logic' [1946], p.21)
     A reaction: This is Ayer's attempt to meet the well known objection of 'turning the tables' on his theory (by asking whether it is tautological or empirically verifiable). However, if it is just a definition, then presumably it is completely arbitrary…
19. Language / D. Propositions / 1. Propositions
Sentences only express propositions if they are meaningful; otherwise they are 'statements' [Ayer]
     Full Idea: I suggest that every grammatically significant indicative sentence expresses a 'statement', but the word 'proposition' will be reserved for what is expressed by sentences that are literally meaningful.
     From: A.J. Ayer (Introduction to 'Language Truth and Logic' [1946], p.10)
     A reaction: We don't have to accept Ayer's over-fussy requirements for what is meaningful to accept that this is a good distinction. Every day we hear statements from people (e.g. politicians) in which we can fish in vain for the underlying proposition.
20. Action / B. Preliminaries of Action / 2. Willed Action / a. Will to Act
Just as you have the impulse to do something, stop [Anon (Cent)]
     Full Idea: Just as you have the impulse to do something, stop.
     From: Anon (Cent) (Centring [c.500 BCE], 64)
     A reaction: Nice. You might train your own will like a dog in this way. It is a counterexample to the simplistic idea that all you need is a belief and a desire, and you have got an action. But (pace Searle, Ideas 3817 + 3818) this does not prove free will.
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / i. Prescriptivism
Moral approval and disapproval concerns classes of actions, rather than particular actions [Ayer]
     Full Idea: The common objects of moral approval and disapproval are not particular actions so much as classes of actions.
     From: A.J. Ayer (Introduction to 'Language Truth and Logic' [1946], p.27)
     A reaction: This 1946 revision of his pure emotivism looks like a move towards Hare's prescriptivism, where classes, rules and principles are seen as the window-dressing of emotivism. It's still a bad theory.
25. Social Practice / A. Freedoms / 5. Freedom of lifestyle
Bondage and liberation are relative terms, which only frighten those already terrified of the universe [Anon (Cent)]
     Full Idea: Since in truth, bondage and freedom are relative, these words are only for those terrified with the universe. The universe is a reflection of minds. As you see many suns in water from one sun, so see bondage and liberation.
     From: Anon (Cent) (Centring [c.500 BCE], 110)
     A reaction: Since most easterners have experienced permanent social repression, their philosophies all encourage them not to worry about it. No wonder marxism, proved popular, when it suggested you could actually change things.
29. Religion / C. Spiritual Disciplines / 4. Zen Buddhism
Feel your whole body saturated with cosmic essence [Anon (Cent)]
     Full Idea: Feel your substance, bones, flesh, blood, saturated with cosmic essence.
     From: Anon (Cent) (Centring [c.500 BCE], 23)
     A reaction: I find this unsatisfactory. Being a sad victim of materialistic western scientific culture, I don't think 'cosmic essence' exists. I could imagine myself full of the stuff, and that might feel good, but I could also imagine I had won the lottery.
Abandon attachment to body, and feel the joy of being everywhere [Anon (Cent)]
     Full Idea: Toss attachment for body aside, realising I am everywhere. One who is everywhere is joyous.
     From: Anon (Cent) (Centring [c.500 BCE], 79)
     A reaction: I really don't think it is wisdom to spend your time imagining things which are not true. I might imagine that some gorgeous film star is in love with me, but I don't recommend it. Live according to nature. We are physical beings.
The serenity in blue sky beyond clouds [Anon (Cent)]
     Full Idea: Simply by looking into blue sky beyond clouds - the serenity.
     From: Anon (Cent) (Centring [c.500 BCE], 59)
     A reaction: Philip Larkin finds the same experience looking through high windows. If we articulate the experience, it seems to combine humility and detachment. The sky makes us insignificant, but the mind can project into the sky.
29. Religion / D. Religious Issues / 2. Immortality / a. Immortality
Imagine fire burning up your whole body, but not you [Anon (Cent)]
     Full Idea: Focus on fire rising through your form from the toes up until the body burns to ashes, but not you.
     From: Anon (Cent) (Centring [c.500 BCE], 28)
     A reaction: Try very hard to persuade yourself that you are immortal, even if you are not. Hm. Zen Buddhism actually contains very little commitment to what is true or false. It explores interesting beliefs like children playing with toys. Very post-modern.