27 ideas
| 21970 | Philosophy attains its goal if one person feels perfect accord between their system and experience [Fichte] |
| Full Idea: If even a single person is completely convinced of his philosophy; ...if his free judgement in philosophising, and what life obtrudes upon him, are perfectly in accord; then in this person philosophy has completed its circuit and attained its goal. | |
| From: Johann Fichte (works [1798], I:512), quoted by A.W. Moore - The Evolution of Modern Metaphysics 06.4 | |
| A reaction: Interesting to hear a famous idealist offering accordance with real life as a criterion for philosophical success. But that is real life, but not as you and I may know it.... His criterion is very subjective. A bad philosopher might attain it? |
| 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. |
| 6912 | For Fichte there is no God outside the ego, and 'our religion is reason' [Fichte, by Feuerbach] |
| Full Idea: For Fichte there is no God outside the ego, and 'our religion is reason'. | |
| From: report of Johann Fichte (works [1798]) by Ludwig Feuerbach - Principles of Philosophy of the Future §17 | |
| A reaction: Fichte was not an atheist, but this seems to be a supreme aphorism for summarising our image of the Englightenment. Personally I subscribe to the Enlightenment ideal (the best life is the rational life), despite doubts about 'pure' reason. |
| 15647 | Truth definitions don't produce a good theory, because they go beyond your current language [Halbach] |
| Full Idea: It is far from clear that a definition of truth can lead to a philosophically satisfactory theory of truth. Tarski's theorem on the undefinability of the truth predicate needs resources beyond those of the language for which it is being defined. | |
| From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1) | |
| A reaction: The idea is that you need a 'metalanguage' for the definition. If I say 'p' is a true sentence in language 'L', I am not making that observation from within language L. The dream is a theory confined to the object language. |
| 15649 | In semantic theories of truth, the predicate is in an object-language, and the definition in a metalanguage [Halbach] |
| Full Idea: In semantic theories of truth (Tarski or Kripke), a truth predicate is defined for an object-language. This definition is carried out in a metalanguage, which is typically taken to include set theory or another strong theory or expressive language. | |
| From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1) | |
| A reaction: Presumably the metalanguage includes set theory because that connects it with mathematics, and enables it to be formally rigorous. Tarski showed, in his undefinability theorem, that the meta-language must have increased resources. |
| 15655 | Should axiomatic truth be 'conservative' - not proving anything apart from implications of the axioms? [Halbach] |
| Full Idea: If truth is not explanatory, truth axioms should not allow proof of new theorems not involving the truth predicate. It is hence said that axiomatic truth should be 'conservative' - not implying further sentences beyond what the axioms can prove. | |
| From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1.3) | |
| A reaction: [compressed] |
| 15654 | If truth is defined it can be eliminated, whereas axiomatic truth has various commitments [Halbach] |
| Full Idea: If truth can be explicitly defined, it can be eliminated, whereas an axiomatized notion of truth may bring all kinds of commitments. | |
| From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1.3) | |
| A reaction: The general principle that anything which can be defined can be eliminated (in an abstract theory, presumably, not in nature!) raises interesting questions about how many true theories there are which are all equivalent to one another. |
| 15650 | Axiomatic theories of truth need a weak logical framework, and not a strong metatheory [Halbach] |
| Full Idea: Axiomatic theories of truth can be presented within very weak logical frameworks which require very few resources, and avoid the need for a strong metalanguage and metatheory. | |
| From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1) |
| 15648 | Instead of a truth definition, add a primitive truth predicate, and axioms for how it works [Halbach] |
| Full Idea: The axiomatic approach does not presuppose that truth can be defined. Instead, a formal language is expanded by a new primitive predicate of truth, and axioms for that predicate are then laid down. | |
| From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1) | |
| A reaction: Idea 15647 explains why Halbach thinks the definition route is no good. |
| 15656 | Deflationists say truth merely serves to express infinite conjunctions [Halbach] |
| Full Idea: According to many deflationists, truth serves merely the purpose of expressing infinite conjunctions. | |
| From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1.3) | |
| A reaction: That is, it asserts sentences that are too numerous to express individually. It also seems, on a deflationist view, to serve for anaphoric reference to sentences, such as 'what she just said is true'. |
| 15657 | To prove the consistency of set theory, we must go beyond set theory [Halbach] |
| Full Idea: The consistency of set theory cannot be established without assumptions transcending set theory. | |
| From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 2.1) |
| 15652 | We can use truth instead of ontologically loaded second-order comprehension assumptions about properties [Halbach] |
| Full Idea: The reduction of 2nd-order theories (of properties or sets) to axiomatic theories of truth may be conceived as a form of reductive nominalism, replacing existence assumptions (for comprehension axioms) by ontologically innocent truth assumptions. | |
| From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1.1) | |
| A reaction: I like this very much, as weeding properties out of logic (without weeding them out of the world). So-called properties in logic are too abundant, so there is a misfit with their role in science. |
| 15651 | Instead of saying x has a property, we can say a formula is true of x - as long as we have 'true' [Halbach] |
| Full Idea: Quantification over (certain) properties can be mimicked in a language with a truth predicate by quantifying over formulas. Instead of saying that Tom has the property of being a poor philosopher, we can say 'x is a poor philosopher' is true of Tom. | |
| From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1.1) | |
| A reaction: I love this, and think it is very important. He talks of 'mimicking' properties, but I see it as philosophers mistakenly attributing properties, when actually what they were doing is asserting truths involving certain predicates. |
| 21973 | Fichte believed in things-in-themselves [Fichte, by Moore,AW] |
| Full Idea: Fichte retained a broadly Kantian conception of how things are in themselves. | |
| From: report of Johann Fichte (works [1798]) by A.W. Moore - The Evolution of Modern Metaphysics 07.2 | |
| A reaction: The contrast is between those who believe in the thing-in-itself, while admitting that we can't know it, and those who deny such a thing. The debate returned 130 years later as verificationism in language. |
| 21914 | We can deduce experience from self-consciousness, without the thing-in-itself [Fichte] |
| Full Idea: We can abandon the thing-in-itself, and aim for 'a complete deduction of all experience from the possibility of self-consciousness'. | |
| From: Johann Fichte (works [1798], I p.425), quoted by Peter B. Lewis - Schopenhauer 3 | |
| A reaction: German Idealism now looks to me like a weird abberation in the history of philosophy, though no doubt it has (like every philosophical theory) some supporters out there somewhere. Schopenhauer called this 'raving nonsense'. |
| 20951 | The absolute I divides into consciousness, and a world which is not-I [Fichte, by Bowie] |
| Full Idea: Fichte's very influential idea is that the subject becomes divided against itself. The absolute I splits into an I (consciousness) and a not-I (the objective world) that are relative to each other. | |
| From: report of Johann Fichte (works [1798]) by Andrew Bowie - Introduction to German Philosophy 3 'Fichtean' | |
| A reaction: This is German Idealism in action. Is there a before and after the split here? I can't make much sense of this idea. It is said that babies spend a while deciding which bits are them and which aren't. There is more to the world than 'not-I'. |
| 21964 | Reason arises from freedom, so philosophy starts from the self, and not from the laws of nature [Fichte] |
| Full Idea: Not by any law of nature do we attain to reason; we achieve it by absolute freedom. ...In philosophy, therefore, we must necessarily start from the self. The materialists' project of deriving the appearance of reason from natural laws is impossible. | |
| From: Johann Fichte (works [1798], I:298), quoted by A.W. Moore - The Evolution of Modern Metaphysics | |
| A reaction: I blame Descartes' Cogito for this misunderstanding. The underlying idea (in Kant, and probably earlier) is that pure reason needs pure free will. Modern thought usually sees reason as extremely impure. |
| 21968 | Abandon the thing-in-itself; things only exist in relation to our thinking [Fichte] |
| Full Idea: We must be rid of the thing-in-itself; for whatever we may think, we are that which thinks therein, and hence nothing could ever come to exist independently of us, for everything is necessarily related to our thinking. | |
| From: Johann Fichte (works [1798], I:501), quoted by A.W. Moore - The Evolution of Modern Metaphysics 06.3 | |
| A reaction: Some statements of idealism are understandable, or even quite plausible, but this one sounds ridiculous. The idea that if human beings die out then reality ceases to exist is absurd humanistic vanity. |
| 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 |
| 21965 | Spinoza could not actually believe his determinism, because living requires free will [Fichte] |
| Full Idea: Spinoza could only think his philosophy, not believe it, for it stood in immediate contradiction to his necessary conviction in daily life, whereby he was bound to regard himself as free and independent. | |
| From: Johann Fichte (works [1798], I:513), quoted by A.W. Moore - The Evolution of Modern Metaphysics 06.2 | |
| A reaction: This seems to be invoking Kant's idea that we must presuppose free will, rather than an assertion that we actually have it. |