20 ideas
5784 | In its primary and formal sense, 'true' applies to propositions, not beliefs [Russell] |
Full Idea: We call a belief true when it is belief in a true proposition, ..but it is to propositions that the primary formal meanings of 'truth' and 'falsehood' apply. | |
From: Bertrand Russell (On Propositions: What they are, and Meaning [1919], §IV) | |
A reaction: I think this is wrong. A proposition such as 'it is raining' would need a date-and-time stamp to be a candidate for truth, and an indexical statement such as 'I am ill' would need to be asserted by a person. Of course, books can contain unread truths. |
5777 | The truth or falsehood of a belief depends upon a fact to which the belief 'refers' [Russell] |
Full Idea: I take it as evident that the truth or falsehood of a belief depends upon a fact to which the belief 'refers'. | |
From: Bertrand Russell (On Propositions: What they are, and Meaning [1919], p.285) | |
A reaction: A nice bold commitment to a controversial idea. The traditional objection is to ask how you are going to formulate the 'facts' except in terms of more beliefs, so you ending up comparing beliefs. Facts are a metaphysical commitment, not an acquaintance. |
5783 | Propositions of existence, generalities, disjunctions and hypotheticals make correspondence tricky [Russell] |
Full Idea: The correspondence of proposition and fact grows increasingly complicated as we pass to more complicated types of propositions: existence-propositions, general propositions, disjunctive and hypothetical propositions, and so on. | |
From: Bertrand Russell (On Propositions: What they are, and Meaning [1919], §IV) | |
A reaction: An important point. Truth must not just work for 'it is raining', but also for maths, logic, tautologies, laws etc. This is why so many modern philosophers have retreated to deflationary and minimal accounts of truth, which will cover all cases. |
17879 | Axiomatising set theory makes it all relative [Skolem] |
Full Idea: Axiomatising set theory leads to a relativity of set-theoretic notions, and this relativity is inseparably bound up with every thoroughgoing axiomatisation. | |
From: Thoralf Skolem (Remarks on axiomatised set theory [1922], p.296) |
17878 | If a 1st-order proposition is satisfied, it is satisfied in a denumerably infinite domain [Skolem] |
Full Idea: Löwenheim's theorem reads as follows: If a first-order proposition is satisfied in any domain at all, it is already satisfied in a denumerably infinite domain. | |
From: Thoralf Skolem (Remarks on axiomatised set theory [1922], p.293) |
17880 | Integers and induction are clear as foundations, but set-theory axioms certainly aren't [Skolem] |
Full Idea: The initial foundations should be immediately clear, natural and not open to question. This is satisfied by the notion of integer and by inductive inference, by it is not satisfied by the axioms of Zermelo, or anything else of that kind. | |
From: Thoralf Skolem (Remarks on axiomatised set theory [1922], p.299) | |
A reaction: This is a plea (endorsed by Almog) that the integers themselves should be taken as primitive and foundational. I would say that the idea of successor is more primitive than the integers. |
17881 | Mathematician want performable operations, not propositions about objects [Skolem] |
Full Idea: Most mathematicians want mathematics to deal, ultimately, with performable computing operations, and not to consist of formal propositions about objects called this or that. | |
From: Thoralf Skolem (Remarks on axiomatised set theory [1922], p.300) |
7720 | Two things can only resemble one another in some respect, and that may reintroduce a universal [Lowe] |
Full Idea: A problem for resemblance nominalism is that in saying that two particulars 'resemble' one another, it is necessary to specify in what respect they do so (e.g. colour, shape, size), and this threatens to reintroduce what appears to be talk of universals. | |
From: E.J. Lowe (Locke on Human Understanding [1995], Ch.7) | |
A reaction: We see resemblance between faces instantly, long before we can specify the 'respects' of the resemblance. This supports the Humean hard-wired view of resemblance, rather than some appeal to Platonic universals. |
7712 | On substances, Leibniz emphasises unity, Spinoza independence, Locke relations to qualities [Lowe] |
Full Idea: Later philosophers emphasised different strands of Aristotle's concept of substances: Leibniz (in his theory of monads) emphasised their unity; Spinoza emphasised their ontological independence; Locke emphasised their role in relation to qualities. | |
From: E.J. Lowe (Locke on Human Understanding [1995], Ch.4) | |
A reaction: Note that this Aristotelian idea had not been jettisoned in the late seventeenth century, unlike other Aristotelianisms. I think it is only with the success of atomism in chemistry that the idea of substance is forced to recede. |
5780 | The three questions about belief are its contents, its success, and its character [Russell] |
Full Idea: There are three issues about belief: 1) the content which is believed, 2) the relation of the content to its 'objective' - the fact which makes it true or false, and 3) the element which is belief, as opposed to consideration or doubt or desire. | |
From: Bertrand Russell (On Propositions: What they are, and Meaning [1919], §III) | |
A reaction: The correct answers to the questions (trust me) are that propositions are the contents, the relation aimed at is truth, which is a 'metaphysical ideal' of correspondence to facts, and belief itself is an indefinable feeling. See Hume, Idea 2208. |
7710 | Perception is a mode of belief-acquisition, and does not involve sensation [Lowe] |
Full Idea: According to one school of thought, perception is simply a mode of belief-acquisition,and there is no reason to suppose that any element of sensation is literally involved in perception. | |
From: E.J. Lowe (Locke on Human Understanding [1995], Ch.3) | |
A reaction: Blindsight would be an obvious supporting case for this view. I think this point is crucial in understanding what is wrong with Jackson's 'knowledge argument' (involving Mary, see Idea 7377). Sensation gives knowledge, so it can't be knowledge. |
7711 | Science requires a causal theory - perception of an object must be an experience caused by the object [Lowe] |
Full Idea: Only a causal theory of perception will respect the facts of physiology and physics ...meaning a theory which maintains that for a subject to perceive a physical object the subject should enjoy some appropriate perceptual experience caused by the object. | |
From: E.J. Lowe (Locke on Human Understanding [1995], Ch.3) | |
A reaction: If I hallucinate an object, then presumably I am not allowed to say that I 'perceive' it, but that seems to make the causal theory an idle tautology. If we are in virtual reality then there aren't any objects. |
7714 | Personal identity is a problem across time (diachronic) and at an instant (synchronic) [Lowe] |
Full Idea: There is the question of the identity of a person over or across time ('diachronic' personal identity), and there is also the question of what makes for personal identity at a time ('synchronic' personal identity). | |
From: E.J. Lowe (Locke on Human Understanding [1995], Ch.5) | |
A reaction: This seems to me to be the first and most important distinction in the philosophy of personal identity, and they regularly get run together. Locke, for example, has an account of synchronic identity, which is often ignored. It applies to objects too. |
5778 | If we object to all data which is 'introspective' we will cease to believe in toothaches [Russell] |
Full Idea: If privacy is the main objection to introspective data, we shall have to include among such data all sensations; a toothache, for example, is essentially private; a dentist may see the bad condition of your tooth, but does not feel your ache. | |
From: Bertrand Russell (On Propositions: What they are, and Meaning [1919], §II) | |
A reaction: Russell was perhaps the first to see why eliminative behaviourism is a non-starter as a theory of mind. Mental states are clearly a cause of behaviour, so they can't be the same thing. We might 'eliminate' mental states by reducing them, though. |
5779 | There are distinct sets of psychological and physical causal laws [Russell] |
Full Idea: There do seem to be psychological and physical causal laws which are distinct from each other. | |
From: Bertrand Russell (On Propositions: What they are, and Meaning [1919], §II) | |
A reaction: This sounds like the essence of 'property dualism'. Reductive physicalists (like myself) say there is no distinction. Davidson, usually considered a property dualist, claims there are no psycho-physical laws. Russell notes that reduction may be possible. |
7715 | Mentalese isn't a language, because it isn't conventional, or a means of public communication [Lowe] |
Full Idea: 'Mentalese' would be neither conventional nor a means of public communication so that even to call it a language is seriously misleading. | |
From: E.J. Lowe (Locke on Human Understanding [1995], Ch.7) | |
A reaction: It is, however, supposed to contain symbolic representations which are then used as tokens for computation, so it seems close to a language, if (for example) symbolic logic or mathematics were accepted as languages. But who understands it? |
7722 | If meaning is mental pictures, explain "the cat (or dog!) is NOT on the mat" [Lowe] |
Full Idea: If meaning is a private mental picture, what does 'the cat is NOT on the mat' mean, and how does it differ from 'the dog is not on the mat?'. | |
From: E.J. Lowe (Locke on Human Understanding [1995], Ch.7) | |
A reaction: Not insurmountable. We picture an empty mat, combined with a cat (or whatever) located somewhere else. A mental 'picture' of something shouldn't be contrued as a single image in a neat black frame. |
5781 | Our important beliefs all, if put into words, take the form of propositions [Russell] |
Full Idea: The important beliefs, even if they are not the only ones, are those which, if rendered into explicit words, take the form of a proposition. | |
From: Bertrand Russell (On Propositions: What they are, and Meaning [1919], §III) | |
A reaction: This assertion is close to the heart of the twentieth century linking of ontology and epistemology to language. It is open to challenges. Why is non-propositional belief unimportant? Do dogs have important beliefs? Can propositions exist non-verbally? |
5782 | A proposition expressed in words is a 'word-proposition', and one of images an 'image-proposition' [Russell] |
Full Idea: I shall distinguish a proposition expressed in words as a 'word-proposition', and one consisting of images as an 'image-proposition'. | |
From: Bertrand Russell (On Propositions: What they are, and Meaning [1919], §III) | |
A reaction: This, I think, is good, though it raises the question of what exactly an 'image' is when it is non-visual, as when a dog believes its owner called. This distinction prevents us from regarding all knowledge and ontology as verbal in form. |
5776 | A proposition is what we believe when we believe truly or falsely [Russell] |
Full Idea: A proposition may be defined as: what we believe when we believe truly or falsely. | |
From: Bertrand Russell (On Propositions: What they are, and Meaning [1919], p.285) | |
A reaction: If we define belief as 'commitment to truth', Russell's last six words become redundant. "Propositions are the contents of beliefs", it being beliefs which are candidates for truth, not propositions. (Russell agrees, on p.308!) |