Combining Texts

All the ideas for 'Theaetetus', 'Papers of 1906' and 'Language,Truth and Logic'

unexpand these ideas     |    start again     |     specify just one area for these texts


75 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 / D. Nature of Philosophy / 7. Despair over Philosophy
Philosophers are always switching direction to something more interesting [Plato]
     Full Idea: Philosophers are always ready to change direction, if a topic crops up which is more attractive than the one to hand.
     From: Plato (Theaetetus [c.368 BCE], 172d)
     A reaction: Which sounds trivial, but it may be what God does.
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 / 2. Analysis by Division
Understanding mainly involves knowing the elements, not their combinations [Plato]
     Full Idea: A perfect grasp of any subject depends far more on knowing elements than on knowing complexes.
     From: Plato (Theaetetus [c.368 BCE], 206b)
Either a syllable is its letters (making parts as knowable as whole) or it isn't (meaning it has no parts) [Plato]
     Full Idea: Either a syllable is not the same as its letters, in which case it cannot have the letters as parts of itself, or it is the same as its letters, in which case these basic elements are just as knowable as it is.
     From: Plato (Theaetetus [c.368 BCE], 205b)
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.
2. Reason / A. Nature of Reason / 6. Coherence
A rational account is essentially a weaving together of things with names [Plato]
     Full Idea: Just as primary elements are woven together, so their names may be woven together to produce a spoken account, because an account is essentially a weaving together of names.
     From: Plato (Theaetetus [c.368 BCE], 202b)
     A reaction: If justification requires 'logos', and logos is a 'weaving together of names', then Plato might be taken as endorsing the coherence account of justification. Or do the two 'weavings' correspond?
2. Reason / C. Styles of Reason / 3. Eristic
Eristic discussion is aggressive, but dialectic aims to help one's companions in discussion [Plato]
     Full Idea: Eristic discussions involve as many tricks and traps as possible, but dialectical discussions involve being serious and correcting the interlocutor's mistakes only when they are his own fault or the result of past conditioning.
     From: Plato (Theaetetus [c.368 BCE], 167e)
2. Reason / D. Definition / 4. Real Definition
A primary element has only a name, and no logos, but complexes have an account, by weaving the names [Plato]
     Full Idea: A primary element cannot be expressed in an account; it can only be named, for a name is all that it has. But with the things composed of these ...just as the elements are woven together, so the names can woven to become an account.
     From: Plato (Theaetetus [c.368 BCE], 202b01-3)
     A reaction: This is the beginning of what I see as Aristotle's metaphysics, as derived from his epistemology, that is, ontology is what explains, and what we can give an account [logos] of. Aristotle treats this under 'definitions'.
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".
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / a. For mathematical platonism
We master arithmetic by knowing all the numbers in our soul [Plato]
     Full Idea: It must surely be true that a man who has completely mastered arithmetic knows all numbers? Because there are pieces of knowledge covering all numbers in his soul.
     From: Plato (Theaetetus [c.368 BCE], 198b)
     A reaction: This clearly views numbers as objects. Expectation of knowing them all is a bit startling! They also appear to be innate in us, and hence they appear to be Forms. See Aristotle's comment in Idea 645.
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 / B. Change in Existence / 1. Nature of Change
There seem to be two sorts of change: alteration and motion [Plato]
     Full Idea: There are two kinds of change, I think: alteration and motion.
     From: Plato (Theaetetus [c.368 BCE], 181d)
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.
9. Objects / C. Structure of Objects / 8. Parts of Objects / a. Parts of objects
If a word has no parts and has a single identity, it turns out to be the same kind of thing as a letter [Plato]
     Full Idea: If a complex or a syllable has no parts and is a single identity, hasn't it turned out to be the same kind of thing as an element or letter?
     From: Plato (Theaetetus [c.368 BCE], 205d)
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
A sum is that from which nothing is lacking, which is a whole [Plato]
     Full Idea: But this sum now - isn't it just when there is nothing lacking that it is a sum? Yes, necessarily. And won't this very same thing - that from which nothing is lacking - be a whole?
     From: Plato (Theaetetus [c.368 BCE], 205a)
     A reaction: This seems to be right, be rather too vague and potentially circular to be of much use. What is the criterion for deciding that nothing is lacking?
The whole can't be the parts, because it would be all of the parts, which is the whole [Plato]
     Full Idea: The whole does not consist of parts; for it did, it would be all the parts and so would be the sum.
     From: Plato (Theaetetus [c.368 BCE], 204e)
     A reaction: That is, 'the whole is the sum of its parts' is a tautology! The claim that 'the whole is more than the sum of its parts' gets into similar trouble. See Verity Harte on this.
11. Knowledge Aims / A. Knowledge / 1. Knowledge
Things are only knowable if a rational account (logos) is possible [Plato]
     Full Idea: Things which are susceptible to a rational account are knowable.
     From: Plato (Theaetetus [c.368 BCE], 201d)
11. Knowledge Aims / A. Knowledge / 2. Understanding
Expertise is knowledge of the whole by means of the parts [Plato]
     Full Idea: A man has passed from mere judgment to expert knowledge of the being of a wagon when he has done so in virtue of having gone over the whole by means of the elements.
     From: Plato (Theaetetus [c.368 BCE], 207c)
     A reaction: Plato is emphasising that the expert must know the hundred parts of a wagon, and not just the half dozen main components, but here the point is to go over the whole via the parts, and not just list the parts.
11. Knowledge Aims / A. Knowledge / 4. Belief / c. Aim of beliefs
It is impossible to believe something which is held to be false [Plato]
     Full Idea: It is impossible to believe something which is not the case.
     From: Plato (Theaetetus [c.368 BCE], 167a)
11. Knowledge Aims / A. Knowledge / 4. Belief / d. Cause of beliefs
How can a belief exist if its object doesn't exist? [Plato]
     Full Idea: If the object of a belief is what is not, the object of this belief is nothing; but if there is no object to a belief, then that is not belief at all.
     From: Plato (Theaetetus [c.368 BCE], 189a)
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 / 1. Perception
Perception is infallible, suggesting that it is knowledge [Plato]
     Full Idea: Perception is always of something that is, and it is infallible, which suggests that it is knowledge.
     From: Plato (Theaetetus [c.368 BCE], 152c)
Our senses could have been separate, but they converge on one mind [Plato]
     Full Idea: It would be peculiar if each of us were like a Trojan horse, with a whole bunch of senses sitting inside us, rather than that all these perceptions converge onto a single identity (mind, or whatever one ought to call it).
     From: Plato (Theaetetus [c.368 BCE], 184d)
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
You might mistake eleven for twelve in your senses, but not in your mind [Plato]
     Full Idea: Sight or touch might make someone take eleven for twelve, but he could never form this mistaken belief about the contents of his mind.
     From: Plato (Theaetetus [c.368 BCE], 195e)
With what physical faculty do we perceive pairs of opposed abstract qualities? [Plato]
     Full Idea: With what physical faculty do we perceive being and not-being, similarity and dissimilarity, identity and difference, oneness and many, odd and even and other maths, ….fineness and goodness?
     From: Plato (Theaetetus [c.368 BCE], 185d)
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.
Thought must grasp being itself before truth becomes possible [Plato]
     Full Idea: If you can't apprehend being you can't apprehend truth, and so a thing could not be known. Therefore knowledge is not located in immediate experience but in thinking about it, since the latter makes it possible to grasp being and truth.
     From: Plato (Theaetetus [c.368 BCE], 186c)
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.
13. Knowledge Criteria / A. Justification Problems / 1. Justification / b. Need for justification
An inadequate rational account would still not justify knowledge [Plato]
     Full Idea: If you don't know which letters belong together in the right syllables…it is possible for true belief to be accompanied by a rational account and still not be entitled to the name of knowledge.
     From: Plato (Theaetetus [c.368 BCE], 208b)
     A reaction: In each case of justification there is a 'clinching' stage, for which there is never going to be a strict rule. It might be foundational, but equally it might be massive coherence, or no alternative.
13. Knowledge Criteria / A. Justification Problems / 2. Justification Challenges / a. Agrippa's trilemma
Parts and wholes are either equally knowable or equally unknowable [Plato]
     Full Idea: Either a syllable and its letters are equally knowable and expressible in a rational account, or they are both equally unknowable and inexpressible.
     From: Plato (Theaetetus [c.368 BCE], 205e)
     A reaction: Presumably you could explain the syllable by the letters, but not vice versa, but he must mean that the explanation is worthless without the letters being explained too. So all explanation is worthless?
Without distinguishing marks, how do I know what my beliefs are about? [Plato]
     Full Idea: If I only have beliefs about Theaetetus when I don't know his distinguishing mark, how on earth were my beliefs about you rather than anyone else?
     From: Plato (Theaetetus [c.368 BCE], 209b)
     A reaction: This is a rather intellectualist approach to mental activity. Presumably Theaetetus has lots of distinguishing marks, but they are not conscious. Must Socrates know everything?
13. Knowledge Criteria / A. Justification Problems / 3. Internal or External / a. Pro-internalism
A rational account might be seeing an image of one's belief, like a reflection in a mirror [Plato]
     Full Idea: A rational account might be forming an image of one's belief, as in a mirror or a pond.
     From: Plato (Theaetetus [c.368 BCE], 206d)
     A reaction: Not promising, since the image is not going to be clearer than the original, or contain any new information. Maybe it would be clarified by being 'framed', instead of drifting in muddle.
A rational account involves giving an image, or analysis, or giving a differentiating mark [Plato]
     Full Idea: A third sort of rational account (after giving an image, or analysing elements) is being able to mention some mark which differentiates the object in question ('the sun is the brightest heavenly body').
     From: Plato (Theaetetus [c.368 BCE], 208c)
     A reaction: This is Plato's clearest statement of what would be involved in adding the necessary logos to your true belief. An image of it, or an analysis, or an individuation. How about a cause?
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / a. Foundationalism
Maybe primary elements can be named, but not receive a rational account [Plato]
     Full Idea: Maybe the primary elements of which things are composed are not susceptible to rational accounts. Each of them taken by itself can only be named, but nothing further can be said about it.
     From: Plato (Theaetetus [c.368 BCE], 201e)
     A reaction: This still seems to be more or less the central issue in philosophy - which things should be treated as 'primitive', and which other things are analysed and explained using the primitive tools?
13. Knowledge Criteria / B. Internal Justification / 5. Coherentism / b. Pro-coherentism
A rational account of a wagon would mean knowledge of its hundred parts [Plato]
     Full Idea: In the case of a wagon, we may only have correct belief, but someone who is able to explain what it is by going through its hundred parts has got hold of a rational account.
     From: Plato (Theaetetus [c.368 BCE], 207b)
     A reaction: A wonderful example. In science, you know smoking correlates with cancer, but you only know it when you know the mechanism, the causal structure. This may be a general truth.
13. Knowledge Criteria / D. Scepticism / 5. Dream Scepticism
What evidence can be brought to show whether we are dreaming or not? [Plato]
     Full Idea: What evidence could be brought if we were asked at this very moment whether we are asleep and are dreaming all our thoughts?
     From: Plato (Theaetetus [c.368 BCE], 158b)
13. Knowledge Criteria / E. Relativism / 6. Relativism Critique
If you claim that all beliefs are true, that includes beliefs opposed to your own [Plato]
     Full Idea: To say that everyone believes what is the case, is to concede the truth of the oppositions' beliefs; in other words, the person has to concede that he himself is wrong.
     From: Plato (Theaetetus [c.368 BCE], 171a)
How can a relativist form opinions about what will happen in the future? [Plato]
     Full Idea: Does a relativist have any authority to decide about things which will happen in the future?
     From: Plato (Theaetetus [c.368 BCE], 178c)
     A reaction: Nice question! It seems commonsense that such speculations are possible, but without a concept of truth they are ridiculous.
Clearly some people are superior to others when it comes to medicine [Plato]
     Full Idea: In medicine, at least, most people are not self-sufficient at prescribing and effecting cures for themselves, and here some people are superior to others.
     From: Plato (Theaetetus [c.368 BCE], 171e)
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 / A. Modes of Thought / 6. Judgement / b. Error
To explain false belief we should take belief as relating to a proposition's parts, not to the whole thing [Russell]
     Full Idea: To explain belief in what is false we shall have to regard what is called belief in a proposition as not a thought related to the proposition, but rather as a thought related to the constituents of the proposition.
     From: Bertrand Russell (Papers of 1906 [1906], V.321), quoted by Michael Potter - The Rise of Analytic Philosophy 1879-1930 40 '1906'
     A reaction: Russell proposed a new theory of judgement, in order to explain erroneous judgements, given that true propositions are identical with facts. Of course there might be errors about the constituents, as well as about their structure. Othello is his example.
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.
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 / 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 / A. Divine Nature / 6. Divine Morality / c. God is the good
God must be the epitome of goodness, and we can only approach a divine state by being as good as possible [Plato]
     Full Idea: It is impossible for God to be immoral and not to be the acme of morality; and the only way any of us can approximate to God is to become as moral as possible.
     From: Plato (Theaetetus [c.368 BCE], 176c)
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 / 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.
29. Religion / D. Religious Issues / 3. Problem of Evil / a. Problem of Evil
There must always be some force of evil ranged against good [Plato]
     Full Idea: The elimination of evil is impossible, Theodorus; there must always be some force ranged against good.
     From: Plato (Theaetetus [c.368 BCE], 176a)