Combining Philosophers

All the ideas for William W. Tait, Simon Blackburn and Karl Popper

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35 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 / A. Nature of Reason / 5. Objectivity
Scientific objectivity lies in inter-subjective testing [Popper]
     Full Idea: The objectivity of scientific statements lies in the fact that they can be inter-subjectively tested.
     From: Karl Popper (The Logic of Scientific Discovery [1934], p.22), quoted by Reiss,J/Spreger,J - Scientific Objectivity 2.4
     A reaction: Does this mean that objectivity is the same as consensus? A bunch of subjective prejudiced fools can reach a consensus. And in the middle of that bunch there can be one person who is objecfive. Sounds wrong.
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?
5. Theory of Logic / K. Features of Logics / 1. Axiomatisation
Mathematics must be based on axioms, which are true because they are axioms, not vice versa [Tait, by Parsons,C]
     Full Idea: The axiomatic conception of mathematics is the only viable one. ...But they are true because they are axioms, in contrast to the view advanced by Frege (to Hilbert) that to be a candidate for axiomhood a statement must be true.
     From: report of William W. Tait (Intro to 'Provenance of Pure Reason' [2005], p.4) by Charles Parsons - Review of Tait 'Provenance of Pure Reason' §2
     A reaction: This looks like the classic twentieth century shift in the attitude to axioms. The Greek idea is that they must be self-evident truths, but the Tait-style view is that they are just the first steps in establishing a logical structure. I prefer the Greeks.
8. Modes of Existence / C. Powers and Dispositions / 7. Against Powers
Propensities are part of a situation, not part of the objects [Popper]
     Full Idea: Propensities should not be regarded as inherent in an object, such as a die or a penny, but should be regarded as inherent in a situation (of which, of course, the object was part).
     From: Karl Popper (A World of Propensities [1993], p.14), quoted by George Molnar - Powers 6.2
     A reaction: Molnar argues against this claim, and I agree with him. We can see why Popper might prefer this relational view, given that powers often only become apparent in unusual relational situations.
9. Objects / D. Essence of Objects / 11. Essence of Artefacts
Human artefacts may have essences, in their purposes [Popper]
     Full Idea: One might adopt the view that certain things of our own making, such as clocks, may well be said to have 'essences', viz. their 'purposes', and what makes them serve these purposes.
     From: Karl Popper (Conjectures and Refutations [1963], 3.3 n17)
     A reaction: This is from one of the arch-opponents of essentialism. Could we take him on a slippery slope into essences for evolved creatures, or their organs? His argument says admitting an essence for a clock prevents using it for another purpose.
9. Objects / D. Essence of Objects / 15. Against Essentialism
Popper felt that ancient essentialism was a bar to progress [Popper, by Mautner]
     Full Idea: Karl Popper vehemently rejected the essentialism which underpins Plato and Aristotle, taking it to be a major obstacle to political, moral and scientific progress.
     From: report of Karl Popper (Open Society and Its Enemies:Hegel and Marx [1945]) by Thomas Mautner - Penguin Dictionary of Philosophy p.179
     A reaction: This makes Popper sound like an existentialist, which seems unlikely. Modern essentialism would say the opposite about science - that hunting for external imposed laws is a red herring, and we should try to understand essences.
10. Modality / A. Necessity / 11. Denial of Necessity
Asserting a necessity just expresses our inability to imagine it is false [Blackburn]
     Full Idea: To say that we dignify a truth as necessary we are expressing our own mental attitudes - our own inability to make anything of a possible way of thinking which denies it. It is this blank unimaginability which we voice when we use the modal vocabulary.
     From: Simon Blackburn (Spreading the Word [1984], 6.5)
     A reaction: Yes, but why are we unable to imagine it? I accept that the truth or falsity of Goldbach's Conjecture may well be necessary, but I have no imagination one way or the other about it. Philosophers like Blackburn are very alien to me!
10. Modality / C. Sources of Modality / 1. Sources of Necessity
If we are told the source of necessity, this seems to be a regress if the source is not already necessary [Blackburn]
     Full Idea: If we ask why A must be the case, and A is then proved from B, that explains it if B must be so. If the eventual source cites some truth F, then if F just is so, there is strong pressure to feel that the original necessity has not been explained.
     From: Simon Blackburn (Morals and Modals [1987], 1)
     A reaction: [compressed] Ross Cameron wrote a reply to this which I like. I'm fishing for the idea that essence is the source of necessity (as Kit Fine says), but that essence itself is not necessary (as only I say, apparently!).
If something underlies a necessity, is that underlying thing necessary or contingent? [Blackburn, by Hale/Hoffmann,A]
     Full Idea: Blackburn asks of what theorists propose as underlying the necessity of a proposition, the question whether they themselves are conceived as obtaining of necessity or merely contingently.
     From: report of Simon Blackburn (Morals and Modals [1987], p.120-1) by Bob Hale/ Aviv Hoffmann - Introduction to 'Modality' 1
     A reaction: I've seen a reply to this somewhere: I think the thought was that a necessity wouldn't be any less necessary if it had a contingent source, any more than the father of a world champion boxer has to be a world champion boxer.
12. Knowledge Sources / B. Perception / 4. Sense Data / a. Sense-data theory
Visual sense data are an inner picture show which represents the world [Blackburn]
     Full Idea: In the case of vision, sense data are a kind of inner picture show which itself only indirectly represents aspects of the external world.
     From: Simon Blackburn (Oxford Dictionary of Philosophy [1994], p.347)
     A reaction: I'm unsure whether this is correct. Russell says the 'roughness' of the table is the sense datum. If it is even a possibility that there are unsensed sense-data, then they cannot be an aspect of the mind, as Blackburn is suggesting they are.
13. Knowledge Criteria / C. External Justification / 3. Reliabilism / b. Anti-reliabilism
A true belief might be based on a generally reliable process that failed on this occasion [Blackburn]
     Full Idea: Reliabilism is open to the counterexample that a belief may be the result of some generally reliable process (a pressure gauge) which was in fact malfunctioning on this occasion, when we would be reluctant to attribute knowledge to the subject.
     From: Simon Blackburn (Oxford Dictionary of Philosophy [1994], p.327)
     A reaction: Russell's stopped clock that tells the right time twice a day. A good objection. Coming from a reliable source is very good criterion for good justification, but it needs critical assessment.
14. Science / A. Basis of Science / 6. Falsification
Give Nobel Prizes for really good refutations? [Gorham on Popper]
     Full Idea: Popper implies that we should be giving Nobel Prizes to scientists who use severe tests to show us what the world is not like!
     From: comment on Karl Popper (The Logic of Scientific Discovery [1934]) by Geoffrey Gorham - Philosophy of Science 2
     A reaction: A lovely simple point. The refuters are important members of the scientific team, but not the leaders.
Particulars can be verified or falsified, but general statements can only be falsified (conclusively) [Popper]
     Full Idea: Whereas particular reality statements are in principle completely verifiable or falsifiable, things are different for general reality statements: they can indeed be conclusively falsified, they can acquire a negative truth value, but not a positive one.
     From: Karl Popper (Two Problems of Epistemology [1932], p.256), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 18 'Laws'
     A reaction: This sounds like a logician's approach to science, but I prefer to look at coherence, where very little is actually conclusive, and one tinkers with the theory instead.
Falsification is the criterion of demarcation between science and non-science [Popper, by Magee]
     Full Idea: According to Popper, falsification is the criterion of demarcation between science and non-science.
     From: report of Karl Popper (The Logic of Scientific Discovery [1934]) by Bryan Magee - Popper Ch.3
     A reaction: If I propose something which might be falsified in a hundred years, is it science NOW? Suppose my theory appeared to be falsifiable, but (after much effort) it turned out not to be? Suppose I just see a pattern (like quark theory) in a set of facts?
We don't only reject hypotheses because we have falsified them [Lipton on Popper]
     Full Idea: Popper's mistake is to hold that disconfirmation and elimination work exclusively through refutation.
     From: comment on Karl Popper (The Logic of Scientific Discovery [1934]) by Peter Lipton - Inference to the Best Explanation (2nd) 05 'Explanation'
     A reaction: The point is that we reject hypotheses even if they have not actually been refuted, on the grounds that they don't give a good explanation. I agree entirely with Lipton.
If falsification requires logical inconsistency, then probabilistic statements can't be falsified [Bird on Popper]
     Full Idea: In Popper's sense of the word 'falsify', whereby an observation statement falsifies a hypothesis only by being logically inconsistent with it, nothing can ever falsify a probabilistic or statistical hypothesis, which is therefore unscientific.
     From: comment on Karl Popper (The Logic of Scientific Discovery [1934]) by Alexander Bird - Philosophy of Science Ch.5
     A reaction: In general, no prediction can be falsified until the events occur. This seems to be Aristotle's 'sea fight' problem (Idea 1703).
When Popper gets in difficulties, he quietly uses induction to help out [Bird on Popper]
     Full Idea: It is a feature of Popper's philosophy that when the going gets tough, induction is quietly called upon to help out.
     From: comment on Karl Popper (The Logic of Scientific Discovery [1934]) by Alexander Bird - Philosophy of Science Ch.5
     A reaction: This appears to be the central reason for the decline in Popper's reputation as the saviour of science. It would certainly seem absurd to say that you know nothing when you have lots of verification but not a glimmer of falsification.
14. Science / B. Scientific Theories / 2. Aim of Science
Good theories have empirical content, explain a lot, and are not falsified [Popper, by Newton-Smith]
     Full Idea: Popper's principles are roughly that one theory is superior to another if it has greater empirical content, if it can account for the successes of the first theory, and if it has not been falsified (unlike the first theory).
     From: report of Karl Popper (The Logic of Scientific Discovery [1934]) by W.H. Newton-Smith - The Rationality of Science I.6
14. Science / C. Induction / 3. Limits of Induction
There is no such thing as induction [Popper, by Magee]
     Full Idea: According to Popper, induction is a dispensable concept, a myth. It does not exist. There is no such thing.
     From: report of Karl Popper (The Logic of Scientific Discovery [1934]) by Bryan Magee - Popper Ch.2
     A reaction: This is a nice bold summary of the Popper view - that falsification is the underlying rational activity which we mistakenly think is verification by repeated observations. Put like this, Popper seems to be wrong. We obviously learn from experiences.
14. Science / C. Induction / 4. Reason in Induction
Science cannot be shown to be rational if induction is rejected [Newton-Smith on Popper]
     Full Idea: If Popper follows Hume in abandoning induction, there is no way in which he can justify the claims that there is growth of scientific knowledge and that science is a rational activity.
     From: comment on Karl Popper (The Logic of Scientific Discovery [1934]) by W.H. Newton-Smith - The Rationality of Science III.3
14. Science / D. Explanation / 3. Best Explanation / b. Ultimate explanation
Science does not aim at ultimate explanations [Popper]
     Full Idea: I contest the essentialist doctrine that science aims at ultimate explanations, one which cannot be further explained, and which is in no need of any further explanation.
     From: Karl Popper (Conjectures and Refutations [1963], 3.3)
     A reaction: If explanations are causal, this seems to a plea for an infinite regress of causes, which is an odd thing to espouse. Are the explanations verbal descriptions or things in the world. There can be no perfect descriptions, but there may be ultimate things.
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.
20. Action / B. Preliminaries of Action / 2. Willed Action / d. Weakness of will
Akrasia is intelligible in hindsight, when we revisit our previous emotions [Blackburn]
     Full Idea: To make my emotion intelligible [in a weakness of will case] is to look back and recognise that my emotions and dispositions were not quite as I had taken them to be. It is quite useless in such a case to invoke a blanket diagnosis of 'irrationality'.
     From: Simon Blackburn (Ruling Passions [1998], p.191)
     A reaction: So Blackburn rejects the idea of akrasia, because there was never really a conflict. He says rational people always aim to maximise their utility (p.135), and if their own act surprises them, it is just a failure to understand their own rationality.
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / d. Ethical theory
Some philosophers always want more from morality; for others, nature is enough [Blackburn]
     Full Idea: The history of moral theory is largely a history of battles between people who want more (truth, absolutes...) - Plato, Locke, Cudworth, Kant, Nagel - and people content with what we have (nature) - Aristotle, Epicurus, Hobbes, Hume, Stevenson.
     From: Simon Blackburn (Précis of 'Ruling Passions' [2002], p.133)
     A reaction: [Thanks to Neil Sinclair for this one] As a devotee of Aristotle, I like this. I'm always impressed, though, by people who go the extra mile in morality, because they are in the grips of purer and loftier ideals than I am. They also turn into monsters!
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / c. Ethical intuitionism
The main objection to intuitionism in ethics is that intuition is a disguise for prejudice or emotion [Blackburn]
     Full Idea: Critics say that intuitionism in ethics explains nothing, but may merely function as a disguise for prejudice or passion.
     From: Simon Blackburn (Oxford Dictionary of Philosophy [1994], p.198)
     A reaction: If someone claims to have an important moral intuition about something, you should carefully assess the person who has the intuition. I would trust some people a lot.
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / i. Prescriptivism
Critics of prescriptivism observe that it is consistent to accept an ethical verdict but refuse to be bound by it [Blackburn]
     Full Idea: Critics of prescriptivism have noted the problem that whilst accepting a command seems tantamount to setting oneself to obey it, accepting an ethical verdict is, unfortunately, consistent with refusing to be bound by it.
     From: Simon Blackburn (Oxford Dictionary of Philosophy [1994], p.300)
     A reaction: We nearly all of us accept that our behaviour should be better than it actually is, so we accept the oughts but fail to act. Actually 'refusing', though, sounds a bit contradictory.
23. Ethics / C. Virtue Theory / 3. Virtues / h. Respect
The word 'respect' ranges from mere non-interference to the highest levels of reverence [Blackburn]
     Full Idea: The word 'respect' seems to span a spectrum from simply not interfering, passing by on the other side, through admiration, right up to reverence and deference. This makes it uniquely well placed for ideological purposes.
     From: Simon Blackburn (Religion and Respect [2005], p.2)
     A reaction: Most people understand the world perfectly well, but only when they fully understand the context. I've taken to distinguishing conditional from unconditional forms of respect. Everyone is entitled to the unconditional form, which has limits.
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / a. Scientific essentialism
Galilean science aimed at true essences, as the ultimate explanations [Popper]
     Full Idea: The third of the Galilean doctrines of science is that the best, the truly scientific theories, describe the 'essences' or the 'essential natures' of things - the realities which lie behind the appearances. They are ultimate explanations.
     From: Karl Popper (Conjectures and Refutations [1963], 3.3)
     A reaction: This seems to be the seventeenth century doctrine which was undermined by Humeanism, and hence despised by Popper, but is now making a comeback, with a new account of essence and necessity.
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / e. Anti scientific essentialism
Essentialist views of science prevent further questions from being raised [Popper]
     Full Idea: The essentialist view of Newton (due to Roger Cotes) ...prevented fruitful questions from being raised, such as, 'What is the cause of gravity?' or 'Can we deduce Newton's theory from a more general independent theory?'
     From: Karl Popper (Conjectures and Refutations [1963], 3.3)
     A reaction: This is Popper's main (and only) objection to essentialism - that it is committed to ultimate explanations, and smugly terminates science when it thinks it has found them. This does not strike me as a problem with scientific essentialism.