15 ideas
22358 | Scientific objectivity lies in inter-subjective testing [Popper] |
Full Idea: The objectivity of scientific statements lies in the fact that they can be inter-subjectively tested. | |
From: Karl Popper (The Logic of Scientific Discovery [1934], p.22), quoted by Reiss,J/Spreger,J - Scientific Objectivity 2.4 | |
A reaction: Does this mean that objectivity is the same as consensus? A bunch of subjective prejudiced fools can reach a consensus. And in the middle of that bunch there can be one person who is objecfive. Sounds wrong. |
9540 | A 'value-assignment' (V) is when to each variable in the set V assigns either the value 1 or the value 0 [Hughes/Cresswell] |
Full Idea: A 'value-assignment' (V) is when to each variable in the set V assigns either the value 1 or the value 0. | |
From: GE Hughes/M Cresswell (An Introduction to Modal Logic [1968], Ch.1) | |
A reaction: In the interpreted version of the logic, 1 and 0 would become T (true) and F (false). The procedure seems to be called nowadays a 'valuation'. |
9541 | The Law of Transposition says (P→Q) → (¬Q→¬P) [Hughes/Cresswell] |
Full Idea: The Law of Transposition says that (P→Q) → (¬Q→¬P). | |
From: GE Hughes/M Cresswell (An Introduction to Modal Logic [1968], Ch.1) | |
A reaction: That is, if the consequent (Q) of a conditional is false, then the antecedent (P) must have been false. |
9543 | The rules preserve validity from the axioms, so no thesis negates any other thesis [Hughes/Cresswell] |
Full Idea: An axiomatic system is most naturally consistent iff no thesis is the negation of another thesis. It can be shown that every axiom is valid, that the transformation rules are validity-preserving, and if a wff α is valid, then ¬α is not valid. | |
From: GE Hughes/M Cresswell (An Introduction to Modal Logic [1968], Ch.1) | |
A reaction: [The labels 'soundness' and 'consistency' seem interchangeable here, with the former nowadays preferred] |
9544 | A system is 'weakly' complete if all wffs are derivable, and 'strongly' if theses are maximised [Hughes/Cresswell] |
Full Idea: To say that an axiom system is 'weakly complete' is to say that every valid wff of the system is derivable as a thesis. ..The system is 'strongly complete' if it cannot have any more theses than it has without falling into inconsistency. | |
From: GE Hughes/M Cresswell (An Introduction to Modal Logic [1968], Ch.1) | |
A reaction: [They go on to say that Propositional Logic is strongly complete, but Modal Logic is not] |
22188 | Give Nobel Prizes for really good refutations? [Gorham on Popper] |
Full Idea: Popper implies that we should be giving Nobel Prizes to scientists who use severe tests to show us what the world is not like! | |
From: comment on Karl Popper (The Logic of Scientific Discovery [1934]) by Geoffrey Gorham - Philosophy of Science 2 | |
A reaction: A lovely simple point. The refuters are important members of the scientific team, but not the leaders. |
7780 | Falsification is the criterion of demarcation between science and non-science [Popper, by Magee] |
Full Idea: According to Popper, falsification is the criterion of demarcation between science and non-science. | |
From: report of Karl Popper (The Logic of Scientific Discovery [1934]) by Bryan Magee - Popper Ch.3 | |
A reaction: If I propose something which might be falsified in a hundred years, is it science NOW? Suppose my theory appeared to be falsifiable, but (after much effort) it turned out not to be? Suppose I just see a pattern (like quark theory) in a set of facts? |
16830 | We don't only reject hypotheses because we have falsified them [Lipton on Popper] |
Full Idea: Popper's mistake is to hold that disconfirmation and elimination work exclusively through refutation. | |
From: comment on Karl Popper (The Logic of Scientific Discovery [1934]) by Peter Lipton - Inference to the Best Explanation (2nd) 05 'Explanation' | |
A reaction: The point is that we reject hypotheses even if they have not actually been refuted, on the grounds that they don't give a good explanation. I agree entirely with Lipton. |
6794 | If falsification requires logical inconsistency, then probabilistic statements can't be falsified [Bird on Popper] |
Full Idea: In Popper's sense of the word 'falsify', whereby an observation statement falsifies a hypothesis only by being logically inconsistent with it, nothing can ever falsify a probabilistic or statistical hypothesis, which is therefore unscientific. | |
From: comment on Karl Popper (The Logic of Scientific Discovery [1934]) by Alexander Bird - Philosophy of Science Ch.5 | |
A reaction: In general, no prediction can be falsified until the events occur. This seems to be Aristotle's 'sea fight' problem (Idea 1703). |
6795 | When Popper gets in difficulties, he quietly uses induction to help out [Bird on Popper] |
Full Idea: It is a feature of Popper's philosophy that when the going gets tough, induction is quietly called upon to help out. | |
From: comment on Karl Popper (The Logic of Scientific Discovery [1934]) by Alexander Bird - Philosophy of Science Ch.5 | |
A reaction: This appears to be the central reason for the decline in Popper's reputation as the saviour of science. It would certainly seem absurd to say that you know nothing when you have lots of verification but not a glimmer of falsification. |
3856 | Good theories have empirical content, explain a lot, and are not falsified [Popper, by Newton-Smith] |
Full Idea: Popper's principles are roughly that one theory is superior to another if it has greater empirical content, if it can account for the successes of the first theory, and if it has not been falsified (unlike the first theory). | |
From: report of Karl Popper (The Logic of Scientific Discovery [1934]) by W.H. Newton-Smith - The Rationality of Science I.6 |
7779 | There is no such thing as induction [Popper, by Magee] |
Full Idea: According to Popper, induction is a dispensable concept, a myth. It does not exist. There is no such thing. | |
From: report of Karl Popper (The Logic of Scientific Discovery [1934]) by Bryan Magee - Popper Ch.2 | |
A reaction: This is a nice bold summary of the Popper view - that falsification is the underlying rational activity which we mistakenly think is verification by repeated observations. Put like this, Popper seems to be wrong. We obviously learn from experiences. |
3860 | Science cannot be shown to be rational if induction is rejected [Newton-Smith on Popper] |
Full Idea: If Popper follows Hume in abandoning induction, there is no way in which he can justify the claims that there is growth of scientific knowledge and that science is a rational activity. | |
From: comment on Karl Popper (The Logic of Scientific Discovery [1934]) by W.H. Newton-Smith - The Rationality of Science III.3 |
1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
Full Idea: Archelaus was the first person to say that the universe is boundless. | |
From: report of Archelaus (fragments/reports [c.450 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 02.Ar.3 |
5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |
Full Idea: Archelaus wrote that life on Earth began in a primeval slime. | |
From: report of Archelaus (fragments/reports [c.450 BCE]) by Malcolm Schofield - Archelaus | |
A reaction: This sounds like a fairly clearcut assertion of the production of life by evolution. Darwin's contribution was to propose the mechanism for achieving it. We should honour the name of Archelaus for this idea. |