Combining Texts

All the ideas for 'Through the Looking Glass', 'The Problem of Knowledge' and 'A Pragmatic Conception of the A Priori'

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14 ideas

2. Reason / F. Fallacies / 1. Fallacy
Induction assumes some uniformity in nature, or that in some respects the future is like the past [Ayer]
     Full Idea: In all inductive reasoning we make the assumption that there is a measure of uniformity in nature; or, roughly speaking, that the future will, in the appropriate respects, resemble the past.
     From: A.J. Ayer (The Problem of Knowledge [1956], 2.viii)
     A reaction: I would say that nature is 'stable'. Nature changes, so a global assumption of total uniformity is daft. Do we need some global uniformity assumptions, if the induction involved is local? I would say yes. Are all inductions conditional on this?
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
There are several logics, none of which will ever derive falsehoods from truth [Lewis,CI]
     Full Idea: The fact is that there are several logics, markedly different, each self-consistent in its own terms and such that whoever, using it, avoids false premises, will never reach a false conclusion.
     From: C.I. Lewis (A Pragmatic Conception of the A Priori [1923], p.366)
     A reaction: As the man who invented modal logic in five different versions, he speaks with some authority. Logicians now debate which version is the best, so how could that be decided? You could avoid false conclusions by never reasoning at all.
5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle
Excluded middle is just our preference for a simplified dichotomy in experience [Lewis,CI]
     Full Idea: The law of excluded middle formulates our decision that whatever is not designated by a certain term shall be designated by its negative. It declares our purpose to make a complete dichotomy of experience, ..which is only our penchant for simplicity.
     From: C.I. Lewis (A Pragmatic Conception of the A Priori [1923], p.365)
     A reaction: I find this view quite appealing. 'Look, it's either F or it isn't!' is a dogmatic attitude which irritates a lot of people, and appears to be dispensible. Intuitionists in mathematics dispense with the principle, and vagueness threatens it.
5. Theory of Logic / F. Referring in Logic / 1. Naming / a. Names
Names represent a uniformity in experience, or they name nothing [Lewis,CI]
     Full Idea: A name must represent some uniformity in experience or it names nothing.
     From: C.I. Lewis (A Pragmatic Conception of the A Priori [1923], p.368)
     A reaction: I like this because, in the quintessentially linguistic debate about the exact logical role of names, it reminds us that names arise because of the way reality is; they are not sui generis private games for logicians.
7. Existence / A. Nature of Existence / 3. Being / e. Being and nothing
I only wish I had such eyes as to see Nobody! It's as much as I can do to see real people. [Carroll,L]
     Full Idea: "I see nobody on the road," said Alice. - "I only wish I had such eyes," the King remarked. ..."To be able to see Nobody! ...Why, it's as much as I can do to see real people."
     From: Lewis Carroll (C.Dodgson) (Through the Looking Glass [1886], p.189), quoted by A.W. Moore - The Evolution of Modern Metaphysics 07.7
     A reaction: [Moore quotes this, inevitably, in a chapter on Hegel] This may be a better candidate for the birth of philosophy of language than Frege's Groundwork.
10. Modality / A. Necessity / 11. Denial of Necessity
Necessary truths are those we will maintain no matter what [Lewis,CI]
     Full Idea: Those laws and those laws only have necessary truth which we are prepared to maintain, no matter what.
     From: C.I. Lewis (A Pragmatic Conception of the A Priori [1923], p.367)
     A reaction: This bold and simple claim has famously been torpedoed by a well-known counterexample - that virtually every human being will cling on to the proposition "dogs have at some time existed" no matter what, but it clearly isn't a necessary truth.
11. Knowledge Aims / B. Certain Knowledge / 5. Cogito Critique
Knowing I exist reveals nothing at all about my nature [Ayer]
     Full Idea: To know that one exists is not to know anything about oneself any more than knowing that 'this' exists is knowing anything about 'this'.
     From: A.J. Ayer (The Problem of Knowledge [1956], 2.iii)
     A reaction: Descartes proceeds to define himself as a 'thinking thing', inferring that thinking is his essence. Ayer casts nice doubt on that.
To say 'I am not thinking' must be false, but it might have been true, so it isn't self-contradictory [Ayer]
     Full Idea: To say 'I am not thinking' is self-stultifying since if it is said intelligently it must be false: but it is not self-contradictory. The proof that it is not self-contradictory is that it might have been false.
     From: A.J. Ayer (The Problem of Knowledge [1956], 2.iii)
     A reaction: If it doesn't imply a contradiction, then it is not a necessary truth, which is what it is normally taken to be. Is 'This is a sentence' necessarily true? It might not have been one, if the rules of English syntax changed recently.
'I know I exist' has no counterevidence, so it may be meaningless [Ayer]
     Full Idea: If there is no experience at all of finding out that one is not conscious, or that one does not exist, ..it is tempting to say that sentences like 'I exist', 'I am conscious', 'I know that I exist' do not express genuine propositions.
     From: A.J. Ayer (The Problem of Knowledge [1956], 2.iii)
     A reaction: This is, of course, an application of the somewhat discredited verification principle, but the fact that strictly speaking the principle has been sort of refuted does not mean that we should not take it seriously, and be influenced by it.
12. Knowledge Sources / A. A Priori Knowledge / 7. A Priori from Convention
We can maintain a priori principles come what may, but we can also change them [Lewis,CI]
     Full Idea: The a priori contains principles which can be maintained in the face of all experience, representing the initiative of the mind. But they are subject to alteration on pragmatic grounds, if expanding experience shows their intellectual infelicity.
     From: C.I. Lewis (A Pragmatic Conception of the A Priori [1923], p.373)
     A reaction: [compressed] This simply IS Quine's famous 'web of belief' picture, showing how firmly Quine is in the pragmatist tradition. Lewis treats a priori principles as a pragmatic toolkit, which can be refined to be more effective. Not implausible...
14. Science / A. Basis of Science / 6. Falsification
We only discard a hypothesis after one failure if it appears likely to keep on failing [Ayer]
     Full Idea: Why should a hypothesis which has failed the test be discarded unless this shows it to be unreliable; that is, having failed once it is likely to fail again? There is no contradiction in a hypothesis that was falsified being more likely to pass in future.
     From: A.J. Ayer (The Problem of Knowledge [1956], 2.viii)
     A reaction: People may become more likely to pass a test after they have failed at the first attempt. Birds which fail to fly at the first attempt usually achieve total mastery of it. There are different types of hypothesis here.
14. Science / C. Induction / 2. Aims of Induction
Induction passes from particular facts to other particulars, or to general laws, non-deductively [Ayer]
     Full Idea: Inductive reasoning covers all cases in which we pass from a particular statement of fact, or set of them, to a factual conclusion which they do not formally entail. The inference may be to a general law, or by analogy to another particular instance.
     From: A.J. Ayer (The Problem of Knowledge [1956], 2.viii)
     A reaction: My preferred definition is 'learning from experience' - which I take to be the most rational behaviour you could possibly imagine. I don't think a definition should be couched in terms of 'objects' or 'particulars'.
18. Thought / E. Abstraction / 2. Abstracta by Selection
We have to separate the mathematical from physical phenomena by abstraction [Lewis,CI]
     Full Idea: Physical processes present us with phenomena in which the purely mathematical has to be separated out by abstraction.
     From: C.I. Lewis (A Pragmatic Conception of the A Priori [1923], p.367)
     A reaction: This is the father of modal logic endorsing traditional abstractionism, it seems. He is also, though, endorsing the view that a priori knowledge is created by us, with pragmatic ends in view.
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / a. Scientific essentialism
Science seeks classification which will discover laws, essences, and predictions [Lewis,CI]
     Full Idea: The scientific search is for such classification as will make it possible to correlate appearance and behaviour, to discover law, to penetrate to the "essential nature" of things in order that behaviour may become predictable.
     From: C.I. Lewis (A Pragmatic Conception of the A Priori [1923], p.368)
     A reaction: Modern scientific essentialists no longer invoke scare quotes, and I think we should talk of the search for the 'mechanisms' which explain behaviour, but Lewis seems to have been sixty years ahead of his time.