| 1932 | Two Problems of Epistemology |
| p.256 | p.345 | 18284 | Particulars can be verified or falsified, but general statements can only be falsified (conclusively) |
| Full Idea: Whereas particular reality statements are in principle completely verifiable or falsifiable, things are different for general reality statements: they can indeed be conclusively falsified, they can acquire a negative truth value, but not a positive one. | |||
| From: Karl Popper (Two Problems of Epistemology [1932], p.256), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 18 'Laws' | |||
| A reaction: This sounds like a logician's approach to science, but I prefer to look at coherence, where very little is actually conclusive, and one tinkers with the theory instead. |
| 1934 | The Logic of Scientific Discovery |
| p.15 | 3856 | Good theories have empirical content, explain a lot, and are not falsified | |
| 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 |
| p.31 | 7779 | There is no such thing as induction | |
| 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. |
| p.36 | 22188 | Give Nobel Prizes for really good refutations? | |
| 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. |
| p.43 | 7780 | Falsification is the criterion of demarcation between science and non-science | |
| 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? |
| p.52 | 3860 | Science cannot be shown to be rational if induction is rejected | |
| 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 |
| p.87 | 16830 | We don't only reject hypotheses because we have falsified them | |
| 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. |
| p.179 | 6794 | If falsification requires logical inconsistency, then probabilistic statements can't be falsified | |
| 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). |
| p.180 | 6795 | When Popper gets in difficulties, he quietly uses induction to help out | |
| 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. |
| p.22 | p.6 | 22358 | Scientific objectivity lies in inter-subjective testing |
| 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. |
| 1945 | Open Society and Its Enemies:Hegel and Marx |
| p.179 | 5451 | Popper felt that ancient essentialism was a bar to progress | |
| Full Idea: Karl Popper vehemently rejected the essentialism which underpins Plato and Aristotle, taking it to be a major obstacle to political, moral and scientific progress. | |||
| From: report of Karl Popper (Open Society and Its Enemies:Hegel and Marx [1945]) by Thomas Mautner - Penguin Dictionary of Philosophy p.179 | |||
| A reaction: This makes Popper sound like an existentialist, which seems unlikely. Modern essentialism would say the opposite about science - that hunting for external imposed laws is a red herring, and we should try to understand essences. |
| 1963 | Conjectures and Refutations |
| 3.3 | p.104 | 12175 | Galilean science aimed at true essences, as the ultimate explanations |
| Full Idea: The third of the Galilean doctrines of science is that the best, the truly scientific theories, describe the 'essences' or the 'essential natures' of things - the realities which lie behind the appearances. They are ultimate explanations. | |||
| From: Karl Popper (Conjectures and Refutations [1963], 3.3) | |||
| A reaction: This seems to be the seventeenth century doctrine which was undermined by Humeanism, and hence despised by Popper, but is now making a comeback, with a new account of essence and necessity. |
| 3.3 | p.105 | 12176 | Science does not aim at ultimate explanations |
| Full Idea: I contest the essentialist doctrine that science aims at ultimate explanations, one which cannot be further explained, and which is in no need of any further explanation. | |||
| From: Karl Popper (Conjectures and Refutations [1963], 3.3) | |||
| A reaction: If explanations are causal, this seems to a plea for an infinite regress of causes, which is an odd thing to espouse. Are the explanations verbal descriptions or things in the world. There can be no perfect descriptions, but there may be ultimate things. |
| 3.3 | p.106 | 12179 | Essentialist views of science prevent further questions from being raised |
| Full Idea: The essentialist view of Newton (due to Roger Cotes) ...prevented fruitful questions from being raised, such as, 'What is the cause of gravity?' or 'Can we deduce Newton's theory from a more general independent theory?' | |||
| From: Karl Popper (Conjectures and Refutations [1963], 3.3) | |||
| A reaction: This is Popper's main (and only) objection to essentialism - that it is committed to ultimate explanations, and smugly terminates science when it thinks it has found them. This does not strike me as a problem with scientific essentialism. |
| 3.3 n17 | p.106 | 12177 | Human artefacts may have essences, in their purposes |
| Full Idea: One might adopt the view that certain things of our own making, such as clocks, may well be said to have 'essences', viz. their 'purposes', and what makes them serve these purposes. | |||
| From: Karl Popper (Conjectures and Refutations [1963], 3.3 n17) | |||
| A reaction: This is from one of the arch-opponents of essentialism. Could we take him on a slippery slope into essences for evolved creatures, or their organs? His argument says admitting an essence for a clock prevents using it for another purpose. |
| 1993 | A World of Propensities |
| p.14 | p.106 | 11946 | Propensities are part of a situation, not part of the objects |
| Full Idea: Propensities should not be regarded as inherent in an object, such as a die or a penny, but should be regarded as inherent in a situation (of which, of course, the object was part). | |||
| From: Karl Popper (A World of Propensities [1993], p.14), quoted by George Molnar - Powers 6.2 | |||
| A reaction: Molnar argues against this claim, and I agree with him. We can see why Popper might prefer this relational view, given that powers often only become apparent in unusual relational situations. |