Combining Texts

All the ideas for 'Scientific Explanation', 'Elucidation of some points in E.Schrder' and 'The Problem of Knowledge'

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8 ideas

2. Reason / F. Fallacies / 1. Fallacy

19463	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?

2. Reason / F. Fallacies / 4. Circularity

9355	One sort of circularity presupposes a premise, the other presupposes a rule being used [Braithwaite, by Devitt]
	Full Idea: An argument is 'premise-circular' if it aims to establish a conclusion that is assumed as a premise of that very argument. An argument is 'rule-circular' if it aims to establish a conclusion that asserts the goodness of the rule used in that argument.
	From: report of R.B. Braithwaite (Scientific Explanation [1953], p.274-8) by Michael Devitt - There is no a Priori §2
	A reaction: Rule circularity is the sort of thing Quine is always objecting to, but such circularities may be unavoidable, and even totally benign. All the good things in life form a mutually supporting team.

4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set

14238	A class is an aggregate of objects; if you destroy them, you destroy the class; there is no empty class [Frege]
	Full Idea: A class consists of objects; it is an aggregate, a collective unity, of them; if so, it must vanish when these objects vanish. If we burn down all the trees of a wood, we thereby burn down the wood. Thus there can be no empty class.
	From: Gottlob Frege (Elucidation of some points in E.Schröder [1895], p.212), quoted by Oliver,A/Smiley,T - What are Sets and What are they For?
	A reaction: This rests on Cantor's view of a set as a collection, rather than on Dedekind, which allows null and singleton sets.

11. Knowledge Aims / B. Certain Knowledge / 5. Cogito Critique

19461	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.

19459	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.

19460	'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.

14. Science / A. Basis of Science / 6. Falsification

19464	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

19462	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'.