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All the ideas for 'Reportatio', 'Language,Truth and Logic' and 'Mere Possibilities'

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70 ideas

1. Philosophy / D. Nature of Philosophy / 3. Philosophy Defined
Philosophy is a department of logic [Ayer]
     Full Idea: Philosophy is a department of logic.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.2)
     A reaction: Personally I would invert that. Philosophy is concerned with human rationality, of which precise logic appears to be a rather limited subdivision. I see philosophy as the 'master' subject, not the 'servant' subject (as Locke had implied).
1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / e. Philosophy as reason
Philosophers should abandon speculation, as philosophy is wholly critical [Ayer]
     Full Idea: We can overthrow speculative philosophy, and see that the function of philosophy is wholly critical.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.2)
     A reaction: This seems to imply that we CAN speculate, which appeared to be rendered impossible by the verification principle. Personally I think speculation is central to philosophy, but Ayer should always stand as a warning against bogus truth-claims.
1. Philosophy / E. Nature of Metaphysics / 1. Nature of Metaphysics
I don't think Lewis's cost-benefit reflective equilibrium approach offers enough guidance [Stalnaker]
     Full Idea: Lewis articulated and made fashionable the cost-benefit reflective equilibrium methodology, but I have my reservations as it does not offer much guidance.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 1.1)
     A reaction: Stalnaker suggests that this approach has 'run amok' in Lewis's case, giving reality to possible worlds. He spends much effort on showing the 'benefits' of a profoundly implausible view. The same can be said of 4D Perdurantism.
1. Philosophy / E. Nature of Metaphysics / 7. Against Metaphysics
Humeans rejected the a priori synthetic, and so rejected even Kantian metaphysics [Ayer, by Macdonald,C]
     Full Idea: Thinkers from Hume to the logical positivists took exception to Kant's view that some synthetic propositions could be known a priori, and so rejected the possibility of metaphysics as Kant conceived of it.
     From: report of A.J. Ayer (Language,Truth and Logic [1936]) by Cynthia Macdonald - Varieties of Things Ch.1
     A reaction: See Idea 7918 for Kant's epistemological view of metaphysics. This strikes me as a big misunderstanding by empiricists, even though they are quite right to insist on evidence and proof. Metaphysics is essential, but its excess is the worst nonsense.
1. Philosophy / F. Analytic Philosophy / 7. Limitations of Analysis
Critics say analysis can only show the parts, and not their distinctive configuration [Ayer]
     Full Idea: Critics say an analyst is obliged by his atomistic metaphysics to regard an object consisting of parts a, b, c and d in a distinctive configuration as being simply a+b+c+d, and thus giving an entirely false account of its nature.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.2)
     A reaction: Ayer refers the critics to gestatl psychology. Personally I prefer to talk about the ontology rather than the psychology. If we include (as Russell suggests) relations as part of the analysis, there seems to be no problem.
1. Philosophy / G. Scientific Philosophy / 3. Scientism
Philosophy deals with the questions that scientists do not wish to handle [Ayer]
     Full Idea: If there are any questions which science leaves it to philosophy to answer, a straightforward process of elimination must lead to their discovery.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.1)
     A reaction: This is characteristic of the feeble-mindedness that British philosophy slipped into in the age of Wittgenstein, and for a while thereafter. Personally I regard scientists as servants, who are sent off on exploratory errands, and must report back.
3. Truth / H. Deflationary Truth / 2. Deflationary Truth
We cannot analyse the concept of 'truth', because it is simply a mark that a sentence is asserted [Ayer]
     Full Idea: When one says that "Queen Anne is dead" is true or false, these terms 'true' and 'false' connote nothing, but function in the sentence simply as marks of assertion and denial, so there is no sense in asking us to analyse the concept of 'truth'.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.5)
     A reaction: "I am ill" may be true when you say it, and false when I say it. The word 'true' has a useful function in 'x is true if y'. "If that is true, Freddie, I will hit you".
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / a. Systems of modal logic
Non-S5 can talk of contingent or necessary necessities [Stalnaker]
     Full Idea: One can make sense of necessary versus contingent necessities in a non-S5 modal semantics.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 4.3 n17)
     A reaction: In S5 □φ → □□φ, so all necessities are necessary. Does it make any sense to say 'I suppose this might have been necessarily true'?
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / b. Axiom of Extensionality I
In modal set theory, sets only exist in a possible world if that world contains all of its members [Stalnaker]
     Full Idea: One principle of modal set theory should be uncontroversial: a set exists in a given possible world if and only if all of its members exist at that world.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 2.4)
     A reaction: Does this mean there can be no set containing all of my ancestors and future descendants? In no world can we coexist.
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
We regiment to get semantic structure, for evaluating arguments, and understanding complexities [Stalnaker]
     Full Idea: The point of regimentation is to give a perspicuous representation of the semantic structure of an expression, making it easier to evaluate the validity of arguments and to interpret complex statements.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 4.2)
     A reaction: This is an authoritative summary from an expert of why all philosophers must take an interest in logical form.
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / e. or
In 'S was F or some other than S was F', the disjuncts need S, but the whole disjunction doesn't [Stalnaker]
     Full Idea: In 'either Socrates was a philosopher or someone other than Socrates was a philosopher', both propositions expressed by the disjuncts depend for their existence on the existence of Socrates, but the whole disjunction does not.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 4.2)
     A reaction: Nice example, just the sort of thing we pay philosophers to come up with. He is claiming that propositions can exist in possible worlds in which the individuals mentioned do not exist.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / a. Early logicism
Maths and logic are true universally because they are analytic or tautological [Ayer]
     Full Idea: The principles of logic and mathematics are true universally simply because we never allow them to be anything else; …in other words, they are analytic propositions, or tautologies.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.4)
     A reaction: This is obviously a very appealing idea, but it doesn's explain WHY we have invented these particular tautologies (which seem surprisingly useful). The 'science of patterns' can be empirical and a priori and useful (but not tautological).
7. Existence / A. Nature of Existence / 1. Nature of Existence
Some say what exists must do so, and nothing else could possible exist [Stalnaker]
     Full Idea: Some philosophers deny there could have been anything other than what in fact exists, or that anything that exists could have failed to exist. This is developed in very different ways by Wittgenstein (in 'Tractatus'), Lewis and Williamson.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 1)
     A reaction: This could come in various strengths. A weak version would say that, empirically, that all talk of what doesn't exist is vacuous. A strong necessity (Williamson?) that totally rules out other possible existence is a very odd view.
A nominalist view says existence is having spatio-temporal location [Stalnaker]
     Full Idea: A nominalist definition of existence is 'having spatio-temporal location'.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 1.1)
     A reaction: This would evidently be physicalist as well as nominalist. Presumably it fits the 'mosaic' of reality Lewis refers to. I find this view sympathetic. A process of abstraction is required to get the rest of the stuff we talk about.
7. Existence / D. Theories of Reality / 1. Ontologies
Positivists regard ontology as either meaningless or stipulated [Ayer, by Robinson,H]
     Full Idea: Positivists tend to be prejudiced against ontology, regarding very general questions about what sort of things exist either as meaningless, or as questions to be settled by stipulation.
     From: report of A.J. Ayer (Language,Truth and Logic [1936]) by Howard Robinson - Perception IX.4
     A reaction: So much the worse for positivists, because they are missing all the fun. I consider one of the central activities of philosophy to be speculating about explanations. Ontology is at the heart of what explanation aims at.
8. Modes of Existence / B. Properties / 1. Nature of Properties
Properties are modal, involving possible situations where they are exemplified [Stalnaker]
     Full Idea: I take properties and relations to be modal notions. Properties are to be understood in terms of what it would be for them to be exemplified, which means understanding them in terms of a range of possible situations.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 1.2)
     A reaction: I can't make head or tail of a property as anything other than a feature of some entity. Treating properties as a 'range of situations' is just as baffling to me as treating them as sets of objects.
8. Modes of Existence / B. Properties / 10. Properties as Predicates
I accept a hierarchy of properties of properties of properties [Stalnaker]
     Full Idea: I myself am prepared to accept higher-order properties and relations. There is the property of being Socrates, …and the property of being the property of being Socrates, ..and so on.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 4.4)
     A reaction: Elsewhere I have quoted such a hierarchy of vacuous properties as an absurdity that arises if all predicates are treated as properties. Logicians can live with such stuff, given their set hierarchy and so on, but in science and life this is a nonsense.
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / a. Dispositions
Dispositions have modal properties, of which properties things would have counterfactually [Stalnaker]
     Full Idea: Dispositional properties deserve special mention since they seem to be properties that have modal consequences - consequences for what properties the individuals that instantiate them would have in counterfactual circumstances.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 3.4)
     A reaction: I take this to be the key idea in trying to understand modality, but Stalnaker makes this point and then moves swiftly on, because it is so far away from his possible worlds models, in which he has invested a lifetime.
9. Objects / D. Essence of Objects / 7. Essence and Necessity / a. Essence as necessary properties
'Socrates is essentially human' seems to say nothing could be Socrates if it was not human [Stalnaker]
     Full Idea: It seems natural to paraphrase the claim that Socrates is essentially human as the claim that nothing could be Socrates if it was not human.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 4.3)
     A reaction: In ordinary speech it would be emphasising how very human Socrates was (in comparison with Frege, for example). By this token Socrates essentially breathes oxygen, but that is hardly part of his essence.
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
The bundle theory makes the identity of indiscernibles a necessity, since the thing is the properties [Stalnaker]
     Full Idea: On the bundle theory, the identity of indiscernibles (for 'individuals') is a necessary truth, since an individual is just the co-instantiation of all the properties represented by a point in the space of properties.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 3.6)
     A reaction: So much the worse for the bundle theory, I presume. Leibniz did not, I think, hold a bundle theory, but his belief in the identity of indiscernibles seems to have had a theologicial underpinning.
10. Modality / A. Necessity / 3. Types of Necessity
Strong necessity is always true; weak necessity is cannot be false [Stalnaker]
     Full Idea: Prior had a strong and a weak reading of necessity, where strong necessity is truth in all possible worlds, while weak necessity is falsity in no possible world.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 4.3)
     A reaction: [K.Fine 2005:Ch.9 is also cited] The point of the weak one is that in some worlds there might not exist the proposition which is the candidate for truth or falsehood.
10. Modality / C. Sources of Modality / 2. Necessity as Primitive
Necessity and possibility are fundamental, and there can be no reductive analysis of them [Stalnaker]
     Full Idea: My view is that if there were a nonmodal analysis of the modal concepts, that would be a sure sign that we were on the wrong track. Necessity and possibility are fundamental concepts, like truth and existence.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 1.1)
     A reaction: The mystery of modality is tied up with the mystery of time (which is a very big mystery indeed). You get a nice clear grip on the here and now, but time and motion whisk you away to something else. Modality concerns the something else.
10. Modality / C. Sources of Modality / 5. Modality from Actuality
Modal concepts are central to the actual world, and shouldn't need extravagant metaphysics [Stalnaker]
     Full Idea: Modal concepts are central to our understanding of the world - the actual world - and understanding them should not require extravagant metaphysical commitments.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 1)
     A reaction: I agree. Personally I think powers and dispositions do the job nicely. You just have to embrace Leibniz's emphasis on the active nature of reality, and the implausible metaphysics starts to recede.
10. Modality / E. Possible worlds / 1. Possible Worlds / d. Possible worlds actualism
Given actualism, how can there be possible individuals, other than the actual ones? [Stalnaker]
     Full Idea: My main focus is on how, on an actualist interpretation of possible worlds as ways a world might be, one is to account for the possibility that there be individuals other than those that actually exist.
     From: Robert C. Stalnaker (Mere Possibilities [2012], Pref)
     A reaction: The obvious thought would be that they are constructions from components of actual individuals, such as the chimaera, or fictional characters. We need some psychology here, which is not Stalnaker's style.
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / a. Nature of possible worlds
Possible worlds are properties [Stalnaker]
     Full Idea: Possible worlds are (to a first approximation) properties. [p.12] They are properties of the total universe.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 1)
Possible worlds don't reduce modality, they regiment it to reveal its structure [Stalnaker]
     Full Idea: It is not reduction (of modality) but regimentation that the possible-worlds framework provides - a procedure for representing modal discourse, using primitive modal notions, in a way that helps reveal its structure.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 1.2)
     A reaction: I think this is exactly my view. All discussion of the ontology of possible worlds is irrelevant. They no more exist than variables in logic exist. They're good when they clarify, but dubious when they over-simplify.
I think of worlds as cells (rather than points) in logical space [Stalnaker]
     Full Idea: I prefer to think of the possible worlds not as points in logical space but as cells of a relatively fine-grained partition of logical space - a partition that makes all the distinctions we need.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 1.2)
     A reaction: Since he regards possible worlds as simply a means of regimenting our understanding of modality, he can think of possible worlds in any way that suits him. I find it hard work tuning in to his vision.
10. Modality / E. Possible worlds / 3. Transworld Objects / c. Counterparts
Modal properties depend on the choice of a counterpart, which is unconstrained by metaphysics [Stalnaker]
     Full Idea: Things have modal properties only relative to the choice of a counterpart relation, and the choice between alternative counterpart relations is not constrained by the metaphysics.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 3.6)
     A reaction: Stalnaker is sympathetic to counterparts, but this strikes me as a powerful objection to the theory. I take the modal properties of something to be fixed by its actuality.
10. Modality / E. Possible worlds / 3. Transworld Objects / d. Haecceitism
Anti-haecceitism says there is no more to an individual than meeting some qualitative conditions [Stalnaker]
     Full Idea: The anti-haecceitist strategy holds that a purely qualitative characterisation of a possible world would be a complete characterisation; there is, on this view, nothing to being a particular individual other than meeting certain qualitative conditions.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 3)
     A reaction: Not quite the same as the bundle theory of objects, which says the objects are the qualities. This is about individuation, not about ontology (I think). I don't like anti-haecceitism, but I also don't like haecceitism. Hmm.
11. Knowledge Aims / B. Certain Knowledge / 1. Certainty
Only tautologies can be certain; other propositions can only be probable [Ayer]
     Full Idea: No proposition, other than a tautology, can possibly be anything more than a probable hypothesis.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.1)
     A reaction: A nice clear empiricist rejection of all attempts to assert necessary truths about nature. This also seems to be a rejection of empiricist foundationalism. A problem case seems to be introspective observations, which seem irrefutable and obvious.
11. Knowledge Aims / C. Knowing Reality / 2. Phenomenalism
Logical positivists could never give the sense-data equivalent of 'there is a table next door' [Robinson,H on Ayer]
     Full Idea: Logical positivist phenomenalism has few supporters these days; ..no one ever seemed clear what the sense-datum equivalent of 'there is a table in the next room' could be.
     From: comment on A.J. Ayer (Language,Truth and Logic [1936]) by Howard Robinson - Perception IX.4
     A reaction: But do the critics know what they mean by 'there is a table in the next room'? Does it just mean 'I am hoping there is'? You can't refer to the table in the next room without sticking your ontological neck out - and that is 'best explanation'.
Material things are constructions from actual and possible occurrences of sense-contents [Ayer]
     Full Idea: The existence of a material thing is defined in terms of the actual and possible occurrence of the sense-contents which constitute it as a logical construction.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.7)
     A reaction: Obviously we need 'possible' experiences so that unperceived trees can still exist, but it is a can of worms. Is speculation about a possible world an account of possible experiences? Realists want to know WHY we think certain experiences are possible.
12. Knowledge Sources / A. A Priori Knowledge / 4. A Priori as Necessities
We could verify 'a thing can't be in two places at once' by destroying one of the things [Ierubino on Ayer]
     Full Idea: It is possible to challenge the proposition 'a material thing cannot be in two places at once' empirically; if you destroy one object, the other should also instantly be destroyed if they are a single thing.
     From: comment on A.J. Ayer (Language,Truth and Logic [1936], Ch.2) by Virgil Ierubino - works
     A reaction: This leaves us having to decide whether the proposition is metaphysically necessary, or is empirical, or is tautological. This idea inclines me towards the view that it is empirical. Imagine two 'separate' objects which responded identically to stimuli.
12. Knowledge Sources / A. A Priori Knowledge / 5. A Priori Synthetic
Whether geometry can be applied to reality is an empirical question outside of geometry [Ayer]
     Full Idea: Whether a geometry can be applied to the actual physical world or not, is an empirical question which falls outside the scope of the geometry itself.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.4)
     A reaction: This is a key objection to rationalism by empiricists. You may say that geometry applies to your car, but your car may have been pulverised while you were talking. Why, though, did Einstein find non-Euclidean geometry so useful?
12. Knowledge Sources / A. A Priori Knowledge / 7. A Priori from Convention
By changing definitions we could make 'a thing can't be in two places at once' a contradiction [Ayer]
     Full Idea: The proposition that 'a material thing cannot be in two places at once' is not empirical at all, but linguistic; ..we could so alter our definitions that the proposition came to express a self-contradiction instead of a necessary truth.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.2)
     A reaction: This seems a striking anticipation of Quine's famous challenge to the analytic/synthetic distinction.
12. Knowledge Sources / A. A Priori Knowledge / 8. A Priori as Analytic
To say that a proposition is true a priori is to say that it is a tautology [Ayer]
     Full Idea: To say that a proposition is true a priori is to say that it is a tautology.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.4)
     A reaction: This is Ayer's splendidly clearcut anti-rationalism. However, one might concede that one cannot know a priori about remote possible worlds (though I'm not so sure), but still claim a priori extrapolations from our current experiences.
12. Knowledge Sources / B. Perception / 4. Sense Data / a. Sense-data theory
Positivists prefer sense-data to objects, because the vocabulary covers both illusions and perceptions [Ayer, by Robinson,H]
     Full Idea: Positivists prefer the sense-datum vocabulary because it is more inclusive than physical object vocabulary; it can report after-images, hallucinations, illusions and bodily sensations, as well as veridical perceptions.
     From: report of A.J. Ayer (Language,Truth and Logic [1936]) by Howard Robinson - Perception IX.4
     A reaction: The assumption of this is that illusions and perceptions are frequently indistinguishable, but that is just nonsense. Illusions usually appeal to one sense only, when you are ill, and in an unclear way. Sensible people know objects when they see them.
12. Knowledge Sources / B. Perception / 7. Causal Perception
Causal and representative theories of perception are wrong as they refer to unobservables [Ayer]
     Full Idea: The fact that all causal and representative theories of perception treat material things as if they were unobservable entities entitles us to rule them out a priori.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.2)
     A reaction: It seems to me that we can accept a causal/representative account of perception if we think of it in terms of 'best explanation' rather than observables. Explanation requires speculation, which logical positivists can't cope with.
12. Knowledge Sources / C. Rationalism / 1. Rationalism
The main claim of rationalism is that thought is an independent source of knowledge [Ayer]
     Full Idea: The fundamental tenet of rationalism is that thought is an independent source of knowledge.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.4)
     A reaction: Presumably one should add that thought gives synthetic knowledge. Thought is also an experience, so empiricists will always acknowledge that we could have some knowledge (of thought) by thought alone.
12. Knowledge Sources / D. Empiricism / 1. Empiricism
Empiricism lacked a decent account of the a priori, until Ayer said it was entirely analytic [O'Grady on Ayer]
     Full Idea: Ayer's gives an account of the a priori (as analytic) that readily meshes with empiricism, and empiricism had long been lacking an adequate account of the a priori
     From: comment on A.J. Ayer (Language,Truth and Logic [1936]) by Paul O'Grady - Relativism Ch.4
     A reaction: Ayer's logical positivist view was based on Hume's 'relations of ideas', as opposed to 'matters of fact'. Personally I see no reason why some facts about reality shouldn't be self-evident to thought, just as others are self-evident to the senses.
All propositions (especially 'metaphysics') must begin with the senses [Ayer]
     Full Idea: One way to attack a metaphysician would be to enquire from what premises his propositions were deduced. Must he not begin, as other men do, with the evidence of his senses?
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.1)
     A reaction: This simple idea is the core of empiricism. This is a heavily criticised doctrine, but you must start somewhere. Hume and Russell agreed. Don't forget, though, that Descartes's first move is to reject the senses as untrustworthy.
My empiricism logically distinguishes analytic and synthetic propositions, and metaphysical verbiage [Ayer]
     Full Idea: The empiricist doctrine to which we are committed is a logical doctrine concerning the distinction between analytic propositions, synthetic propositions, and metaphysical verbiage.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.7)
     A reaction: This is the tough logical positivist version of empiricism. The whole project stumbles on the relationship between a synthetic proposition and its verifying experiences. How close? What of wild speculations? The analytic part is interesting, though.
12. Knowledge Sources / D. Empiricism / 4. Pro-Empiricism
It is further sense-experience which informs us of the mistakes that arise out of sense-experience [Ayer]
     Full Idea: It is further sense-experience which informs us of the mistakes that arise out of sense-experience.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.1)
     A reaction: This is a wonderfull plain-spoken challenge to anyone who thinks they can demonstrate facts a priori about reality. 'I see this object in two places at once'? 'This object appears to be both red and green'?
12. Knowledge Sources / D. Empiricism / 5. Empiricism Critique
Empiricism, it is said, cannot account for our knowledge of necessary truths [Ayer]
     Full Idea: The objection which is commonly brought against empiricism is that it is impossible on empiricist principles to account for our knowledge of necessary truths.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.4)
     A reaction: This criticism goes back at least to Leibniz. Ayer's distinctive contribution to empiricism (with help) is to emphasise that we can only know necessities if they are tautologies. Hume always challenged our knowledge of natural necessities.
14. Science / C. Induction / 2. Aims of Induction
The induction problem is to prove generalisations about the future based on the past [Ayer]
     Full Idea: The problem of induction is (roughly) finding a way to prove that certain empirical generalisations which are derived from past experience will hold good also in the future.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.2)
     A reaction: This doesn't seem to be the only problem. It seems self-evident (since Hume) that you cannot use deductive reasoning to prove that the future will be like the past. In fact, we should obviously be cautious, as things could easily change.
14. Science / C. Induction / 3. Limits of Induction
We can't use the uniformity of nature to prove induction, as that would be circular [Ayer]
     Full Idea: It is often said that we can justify induction by invoking the uniformity of nature, but that principle merely states (in a misleading fashion) the assumption that past experience is a reliable guide to the future.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.2)
     A reaction: That is correct, but it seems to me that if you take the uniformity of nature as a provisional unproven axiom, then induction is an account of how rational creatures cope with the situation. If nature ceases to be uniform, our reason cannot cope.
15. Nature of Minds / A. Nature of Mind / 4. Other Minds / b. Scepticism of other minds
Other minds are 'metaphysical' objects, because I can never observe their experiences [Ayer]
     Full Idea: On the view that we are discussing, I must regard other people as metaphysical objects; for it is assumed that their experiences are completely inaccessible to my observation.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.7)
     A reaction: 'Metaphysical' is here a dirty word. This is the strictly empirical view of other minds, which pushes Ayer towards behaviourism on this subject. He should have asked about the 'best explanation' of the behaviour of others'.
15. Nature of Minds / A. Nature of Mind / 4. Other Minds / c. Knowing other minds
A conscious object is by definition one that behaves in a certain way, so behaviour proves consciousness [Ayer]
     Full Idea: If I know that an object behaves in every way as a conscious being must, by definition, behave, then I know that it is really conscious. This is an analytical proposition.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.7)
     A reaction: This treats the Turing test as proof of consciousness, and is open to all the usual objections to behaviourism. To say behaviour IS consciousness is ridiculous. It just counts as evidence. Presumably Ayer would later have become a functionalist.
16. Persons / B. Nature of the Self / 5. Self as Associations
If the self is meaningful, it must be constructed from sense-experiences [Ayer]
     Full Idea: The self, if it is not to be treated as a metaphysical entity, must be held to be a logical construction out of sense-experiences.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.7)
     A reaction: It is striking how people differ in their reports when they try to see the self by introspection. The self could be beyond sense-experience, and yet still be the best explanation of what we actually DO experience. It is a 'transcendental sensation'?
16. Persons / B. Nature of the Self / 7. Self and Body / a. Self needs body
Two experiences belong to one self if their contents belong with one body [Ayer]
     Full Idea: For any two sense-experiences to belong to the sense-history of the same self it is necessary and sufficient that they should contain organic sense-contents which are elements of the same body.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.7)
     A reaction: This makes more sense if you are a realist about organic bodies, but less sense if (like Ayer) you define the body in terms of sense-experiences. It is a stab at what is now called 'animalism', but needs an account of brain transplant thought-experiments.
Empiricists can define personal identity as bodily identity, which consists of sense-contents [Ayer]
     Full Idea: We have solved Hume's problem by defining personal identity in terms of bodily identity, and bodily identity is to be defined in terms of the resemblance and continuity of sense-contents.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.7)
     A reaction: This is a phenomenalist account of personal identity, so it has no independent account of the body apart from the contents of the mind. Personally I think we must distinguish 'central' mental events from 'peripheral' ones.
17. Mind and Body / A. Mind-Body Dualism / 8. Dualism of Mind Critique
The supposed 'gulf' between mind and matter is based on the senseless concept of 'substances' [Ayer]
     Full Idea: The problems of bridging the 'gulf' between mind and matter, in knowledge or in action, are all fictitious problems arising out of the senseless metaphysical conception of mind and matter as 'substances'.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.7)
     A reaction: He is presumably implying that there is only one 'substance', the stuff of physics, thus voting for Spinoza's dual aspect theory. There could still be a 'gulf', between incommensurable properties, or untranslatable levels of description.
18. Thought / C. Content / 6. Broad Content
How can we know what we are thinking, if content depends on something we don't know? [Stalnaker]
     Full Idea: How can we know what we ourselves are thinking if the very existence of the content of our thought may depend on facts of which we are ignorant?
     From: Robert C. Stalnaker (Mere Possibilities [2012], 5)
     A reaction: This has always been my main doubt about externalism. I may defer to experts about what I intend by an 'elm' (Putnam's example), but what I mean by elm is thereby a fuzzy tall tree with indeterminate leaves. I don't know the meaning of 'elm'!
19. Language / A. Nature of Meaning / 5. Meaning as Verification
A sentence is factually significant to someone if they know how to verify its proposition [Ayer]
     Full Idea: A sentence is factually significant to any given person, if, and only if, he knows how to verify the proposition which it purports to express.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.1)
     A reaction: 'I can't verify it, but I know a bloke who can'? 'If only I could think of a way to verify x'? 'This is unverifiable, but it is the only remaining possibility'? 'X is unverifiable, but it would nice if it was true'? Etc.
Factual propositions imply (in conjunction with a few other premises) possible experiences [Ayer]
     Full Idea: The mark of a genuinely factual proposition is that some experiential propositions can be deduced from it in conjunction with certain other premises without being deducible from those premises alone.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.1)
     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. Verificationism kept meeting problems of this kind.
Tautologies and empirical hypotheses form the entire class of significant propositions [Ayer]
     Full Idea: Tautologies and empirical hypotheses form the entire class of significant propositions.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.1)
     A reaction: This appears to be false. Possibly the problem is that Ayer takes the whole proposition to be the unit of meaning, but actually meaninfulness only requires that we build up a claim about a possible world from semantic units. Blue bees live on square suns.
19. Language / C. Assigning Meanings / 2. Semantics
We still lack an agreed semantics for quantifiers in natural language [Stalnaker]
     Full Idea: We still do not know how to give a direct semantics for the quantifiers of a natural language; that is something that we still do not know how to do (or at least how it is done remains controversial).
     From: Robert C. Stalnaker (Mere Possibilities [2012], 4)
     A reaction: I am struck by how rapidly the domain of quantification changes, even in mid-sentence, in the course of an ordinary conversation. This is decided almost entirely by context, not by pure ('direct'?) semantics.
19. Language / C. Assigning Meanings / 8. Possible Worlds Semantics
Possible world semantics may not reduce modality, but it can explain it [Stalnaker]
     Full Idea: Most theorists agree that possible worlds semantics cannot provide an analysis of modal concepts which is an eliminative reduction, but it can still provide an explanation of the meanings of modal expressions.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 2.2)
     A reaction: Stalnaker cites Kit Fine for the view that there is no reduction of modality, which Fine takes to be primitive. Stalnaker defends the semantics, while denying the reduction which Lewis thought possible.
19. Language / D. Propositions / 1. Propositions
I take propositions to be truth conditions [Stalnaker]
     Full Idea: I will defend the view that propositions are truth conditions.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 1.2)
     A reaction: This sounds close to the Russellian view, which I take to equate propositions (roughly) with facts or states of affairs. But are 'truth conditions' in the world or in the head?
A theory of propositions at least needs primitive properties of consistency and of truth [Stalnaker]
     Full Idea: A minimal theory of propositions can make do with just two primitive properties: a property of consistency applied to sets of propositions, and a property of truth applied to propositions.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 2)
     A reaction: I would have thought a minimal theory would need some account of what a proposition is supposed to be (since there seems to be very little agreement about that). Stalnaker goes on to sketch a theory.
19. Language / D. Propositions / 3. Concrete Propositions
Propositions presumably don't exist if the things they refer to don't exist [Stalnaker]
     Full Idea: It seems plausible that singular propositions are object-dependent in the sense that the proposition would not exist if the individual did not. It is also plausible that some objects exist contingently, and there are singular propositions about them.
     From: Robert C. Stalnaker (Mere Possibilities [2012], 2)
     A reaction: This replies to the view that possible worlds are maximal sets of propositions, and so must exist for the worlds to exist; e.g. Lowe 1999:248. That is yet another commonplace of contemporary philosophy which I find utterly bewildering.
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / c. Ethical intuitionism
Moral intuition is worthless if there is no criterion to decide between intuitions [Ayer]
     Full Idea: Unless it is possible to provide some criterion by which one may decide between conflicting intuitions, a mere appeal to intuition is worthless as a test of a proposition's validity.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.6)
     A reaction: It is a bit much to expect a 'proof' of its 'validity'! If moral judgements are reflected in consequences, then reliable intuitions (i.e. wisdom) could be demonstrated by getting it right (for happiness, or flourishing).
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / h. Expressivism
Ayer defends the emotivist version of expressivism [Ayer, by Smith,M]
     Full Idea: Ayer defends emotivism, which is his own favoured form of expressivism.
     From: report of A.J. Ayer (Language,Truth and Logic [1936], Ch.6) by Michael Smith - The Moral Problem 2.1
     A reaction: A helpful distinction of terminology. Expressivism is the broad theory, and emotivism is a sub-type, saying that it is emotions which are expressed. The alternative (such as Prescriptivism) is to express pro- and con- attitudes.
To say an act is wrong makes no further statement about it, but merely expresses disapproval [Ayer]
     Full Idea: In adding 'You acted wrongly in…' to 'you stole my money' I am not making any further statement about it; I am simply evincing my moral disapproval of it.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.6)
     A reaction: A basic claim of emotivism. Perhaps an understandable response to (e.g.) Kantian claims that we have duties, but to no one in particular. Most people mean by moral criticism that there will be long-term bad consequences, or virtue is lacking.
28. God / A. Divine Nature / 3. Divine Perfections
God is not wise, but more-than-wise; God is not good, but more-than-good [William of Ockham]
     Full Idea: God is not wise, but more-than-wise; God is not good, but more-than-good.
     From: William of Ockham (Reportatio [1330], III Q viii)
     A reaction: [He is quoting 'Damascene'] I quote this for interest, but I very much doubt whether Damascene or William knew what it meant, and I certainly don't. There seems to have been a politically correct desire to invent super-powers for God.
28. God / A. Divine Nature / 4. Divine Contradictions
A person with non-empirical attributes is unintelligible. [Ayer]
     Full Idea: The notion of a person whose essential attributes are non-empirical is not an intelligible notion at all.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.6)
     A reaction: Non-empirical and non-causal are not quite the same thing. A being which never had any effects is a bizarre, and probably pointless, fantasy. A being which affected our world (through ideas, say) but is unobservable is a perfectly good theory.
28. God / B. Proving God / 2. Proofs of Reason / b. Ontological Proof critique
When we ascribe an attribute to a thing, we covertly assert that it exists [Ayer]
     Full Idea: When we ascribe an attribute to a thing, we covertly assert that it exists.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.1)
     A reaction: This is an unsurprising endorsement from logical positivism that Kant's claim that the ontological argument is probably tautological is correct. We could of course say "Imagine a non-existent being with dirty toenails".
28. God / C. Attitudes to God / 4. God Reflects Humanity
We could never form a concept of God's wisdom if we couldn't abstract it from creatures [William of Ockham]
     Full Idea: What we abstract is said to belong to perfection in so far as it can be predicated of God and can stand for Him. For if such a concept could not be abstracted from a creature, then in this life we could not arrive at a cognition of God's wisdom.
     From: William of Ockham (Reportatio [1330], III Q viii)
     A reaction: This seems to be the germ of an important argument. Without the ability to abstract from what is experienced, we would not be able to apply general concepts to things which are beyond experience. It is a key idea for empiricism.
28. God / C. Attitudes to God / 5. Atheism
If theism is non-sensical, then so is atheism. [Ayer]
     Full Idea: If the assertion that there is a god is non-sensical, then the atheist's assertion that there is no god is equally non-sensical.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.6)
     A reaction: Ayer urgently needs the concept of 'best explanation'. If we observe only footprints, we infer creatures; if there are no footprints, lack of creatures looks like a good theory. The design argument is perfectly meaningful.
29. Religion / D. Religious Issues / 1. Religious Commitment / c. Religious Verification
The 'truths' expressed by theists are not literally significant [Ayer]
     Full Idea: There cannot be any transcendent truths of religion, for the sentences which the theist uses to express such 'truths' are not literally significant.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.6)
     A reaction: Ayer claims that only tautologies or empirically verifiable statements have literal significance. I say speculations, wild theories and fantasies are perfectly meaningful. Nevertheless, the words of many hymns and prayers look like empty rhetoric.