15 ideas
18696 | The vagueness of truthmaker claims makes it easier to run anti-realist arguments [Button] |
Full Idea: The sheer lack of structure demanded by truthmaker theorists means that it is easier to run model-theoretic arguments against them than against correspondence theorists. | |
From: Tim Button (The Limits of Reason [2013], 02.3) | |
A reaction: Truthmaking is a vague relation, where correspondence is fairly specific. Model arguments say you can keep the sentences steady, but shuffle around what they refer to. |
18701 | The coherence theory says truth is coherence of thoughts, and not about objects [Button] |
Full Idea: According to the coherence theory of truth, for our thoughts to be true is not for them to be about objects, but only for them to cohere with one another. This is rather terrifying. | |
From: Tim Button (The Limits of Reason [2013], 14.2) | |
A reaction: Davidson espoused this view in 1983, but then gave it up. It strikes me as either a daft view of truth, or a denial of truth. The coherence theory of justification, on the other hand, is correct. |
18694 | Permutation Theorem: any theory with a decent model has lots of models [Button] |
Full Idea: The Permutation Theorem says that any theory with a non-trivial model has many distinct isomorphic models with the same domain. | |
From: Tim Button (The Limits of Reason [2013], 02.1) | |
A reaction: This may be the most significant claim of model theory, since Putnam has erected an argument for anti-realism on it. See the ideas of Tim Button. |
18692 | Realists believe in independent objects, correspondence, and fallibility of all theories [Button] |
Full Idea: External realists have three principles: Independence - the world is objects that are independent of mind, language and theory; Correspondence - truth involves some correspondence of thoughts and things; Cartesian - an ideal theory might be false. | |
From: Tim Button (The Limits of Reason [2013], 01.1-3) | |
A reaction: [compressed; he cites Descartes's Demon for the third] Button is setting these up as targets. I subscribe to all three, in some form or other. Of course, as a theory approaches the success implying it is 'ideal', it becomes highly likely to be accurate. |
18693 | Indeterminacy arguments say if a theory can be made true, it has multiple versions [Button] |
Full Idea: Indeterminacy arguments aim to show that if there is any way to make a theory true, then there are many ways to do so. | |
From: Tim Button (The Limits of Reason [2013], 02.1) | |
A reaction: Button says the simplest indeterminacy argument is Putnam's Permutation Argument - that you can shuffle the objects in a formal model, without affecting truth. But do we belief that metaphysics can be settled in this sort of way? |
18695 | An ideal theory can't be wholly false, because its consistency implies a true model [Button] |
Full Idea: If realists think an ideal theory could be false, then the theory is consistent, and hence complete, and hence finitely modellable, and hence it is guaranteed that there is some way to make it true. | |
From: Tim Button (The Limits of Reason [2013], 02.2) | |
A reaction: [compressed] This challenges the realists' supposed claim that even the most ideal of theories could possibly be false. Presumably for a theory to be 'ideal' is not all-or-nothing. Are we capable of creating a fully ideal theory? [Löwenheim-Skolem] |
16978 | If conceivability is a priori coherence, that implies possibility [Tahko] |
Full Idea: Maybe conceivability could be understood as a priori coherence, which implies possibility. | |
From: Tuomas E. Tahko (The Epistemology of Essence (draft) [2013], 3.2) | |
A reaction: I'm not quite sure why 'a priori' has to be there. Assessing conceivability just is assessing coherence. That couches it as a rational activity, rather than as a purely imaginary one. Trying to conceive a square circle isn't just daydreaming. |
2614 | Modern phenomenalism holds that objects are logical constructions out of sense-data [Ayer] |
Full Idea: Nowadays phenomenalism is held to be a theory of perception which says that physical objects are logical constructions out of sense-data. | |
From: A.J. Ayer (Phenomenalism [1947], §1) |
2615 | The concept of sense-data allows us to discuss appearances without worrying about reality [Ayer] |
Full Idea: The introduction of the term 'sense-datum' is a means of referring to appearances without prejudging the question of what it is, if anything, that they are appearances of. | |
From: A.J. Ayer (Phenomenalism [1947], §1) |
18700 | Cartesian scepticism doubts what is true; Kantian scepticism doubts that it is sayable [Button] |
Full Idea: Cartesian scepticism agonises over whether our beliefs are true or false, whereas Kantian scepticism agonises over how it is even possible for beliefs to be true or false. | |
From: Tim Button (The Limits of Reason [2013], 07.2) | |
A reaction: Kant's question is, roughly, 'how can our thoughts succeed in being about the world?' Kantian scepticism is the more drastic, and looks vulnerable to a turning of the tables, but asking how Kantian worries can even be expressed. |
18698 | Predictions give the 'content' of theories, which can then be 'equivalent' or 'adequate' [Button] |
Full Idea: The empirical 'content' of a theory is all its observable predictions. Two theories with the same predictions are empirically 'equivalent'. A theory which gets it all right at this level is empirically 'adequate'. | |
From: Tim Button (The Limits of Reason [2013], 05.1) |
16975 | Essences are used to explain natural kinds, modality, and causal powers [Tahko] |
Full Idea: Essences are supposed to do a lot of explanatory work: natural kinds can be identified in terms of their essences, metaphysical modality can be reduced to essence, the causal power of objects can be explained with the help of essence. | |
From: Tuomas E. Tahko (The Epistemology of Essence (draft) [2013], 1) | |
A reaction: Natural kinds and modality are OK with me, but I'm dubious about the third one. If an essence explains something's causal powers, I have no idea what an essence might be. Essence are largely characterised in terms of causal powers. |
18697 | A sentence's truth conditions are all the situations where it would be true [Button] |
Full Idea: A sentence's truth conditions comprise an exhaustive list of the situations in which that sentence would be true. | |
From: Tim Button (The Limits of Reason [2013], 03.4) | |
A reaction: So to know its meaning you must know those conditions? Compare 'my cat is licking my finger' with 'dramatic events are happening in Ethiopia'. It should take an awful long time to grasp the second sentence. |
16976 | Scientific essentialists tend to characterise essence in terms of modality (not vice versa) [Tahko] |
Full Idea: The conception of essence taken for granted in much of the 'scientific essentialist' literature is that essence can be explained in terms of modality (rather than the other way round). | |
From: Tuomas E. Tahko (The Epistemology of Essence (draft) [2013], 2.1) | |
A reaction: [He cites Ellis and Bird] That is, presumably, that they are inclined to say that the essence of gold is a set of necessary properties. Maybe conceptual necessities dictate the properties of gold, and they in turn dictate metaphysical necessities? |
16977 | If essence is modal and laws are necessary, essentialist knowledge is found by scientists [Tahko] |
Full Idea: If essence is conceived in terms of modality and the laws of nature are metaphysically necessary, it seems that the laws of nature constitute essentialist knowledge, so the discovery of essences is mostly due to scientists. | |
From: Tuomas E. Tahko (The Epistemology of Essence (draft) [2013], 2.1) | |
A reaction: This seems muddled to me. The idea that the laws themselves are essences is way off target. No one thinks all knowledge of necessities is essentialist. Mumford, for example, doesn't even believe in laws. |