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All the ideas for 'Thinking About Mathematics', 'The Philosophy of Logical Atomism' and 'The Rationalists'

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50 ideas

1. Philosophy / E. Nature of Metaphysics / 4. Metaphysics as Science
The business of metaphysics is to describe the world [Russell]
     Full Idea: It seems to me that the business of metaphysics is to describe the world.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], §III)
     A reaction: At least he believed in metaphysics. Presumably he intends to describe the world in terms of its categories, rather than cataloguing every blade of grass.
2. Reason / B. Laws of Thought / 6. Ockham's Razor
Reducing entities and premisses makes error less likely [Russell]
     Full Idea: You diminish the risk of error with every diminution of entities and premisses.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], §VIII)
     A reaction: If there are actually lots of entities, you would increase error if you reduced them too much. Ockham's Razor seems more to do with the limited capacity of the human mind than with the simplicity or complexity of reality. See Idea 4456.
3. Truth / B. Truthmakers / 5. What Makes Truths / a. What makes truths
Facts make propositions true or false, and are expressed by whole sentences [Russell]
     Full Idea: A fact is the kind of thing that makes a proposition true or false, …and it is the sort of thing that is expressed by a whole sentence, not by a single name like 'Socrates'.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], §I)
     A reaction: It is important to note a point here which I consider vital - that Russell keeps the idea of a fact quite distinct from the language in which it is expressed. Facts are a 'sort of thing', of the kind which are now referred to as 'truth-makers'.
3. Truth / B. Truthmakers / 8. Making General Truths
Not only atomic truths, but also general and negative truths, have truth-makers [Russell, by Rami]
     Full Idea: In 1918 Russell held that beside atomic truths, also general and negative truths have truth-makers.
     From: report of Bertrand Russell (The Philosophy of Logical Atomism [1918]) by Adolph Rami - Introduction: Truth and Truth-Making note 04
4. Formal Logic / F. Set Theory ST / 3. Types of Set / c. Unit (Singleton) Sets
Normally a class with only one member is a problem, because the class and the member are identical [Russell]
     Full Idea: With the ordinary view of classes you would say that a class that has only one member was the same as that one member; that will land you in terrible difficulties, because in that case that one member is a member of that class, namely, itself.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], §VII)
     A reaction: The problem (I think) is that classes (sets) were defined by Frege as being identical with their members (their extension). With hindsight this may have been a mistake. The question is always 'why is that particular a member of that set?'
5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle
Intuitionists deny excluded middle, because it is committed to transcendent truth or objects [Shapiro]
     Full Idea: Intuitionists in mathematics deny excluded middle, because it is symptomatic of faith in the transcendent existence of mathematical objects and/or the truth of mathematical statements.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 1.2)
     A reaction: There are other problems with excluded middle, such as vagueness, but on the whole I, as a card-carrying 'realist', am committed to the law of excluded middle.
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
In a logically perfect language, there will be just one word for every simple object [Russell]
     Full Idea: In a logically perfect language, there will be one word and no more for every simple object.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], §II)
     A reaction: In other words, there would be no universals, only names? All that matters is that a language can successfully refer (unambiguously) to anything it wishes to. There must be better ways than Russell's lexical explosion.
Romulus does not occur in the proposition 'Romulus did not exist' [Russell]
     Full Idea: Romulus does not occur in the proposition 'Romulus did not exist'.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], §VI)
     A reaction: A very nice paradoxical assertion, which captures the problem of finding the logical form for negative existential statements. Presumably the proposition refers to the mythical founder of Rome, though. He is not, I suppose, rigidly designated.
5. Theory of Logic / F. Referring in Logic / 1. Naming / a. Names
You can understand 'author of Waverley', but to understand 'Scott' you must know who it applies to [Russell]
     Full Idea: If you understand English you would understand the phrase 'the author of Waverley' if you had not heard it before, whereas you would not understand the meaning of 'Scott', because to know the meaning of a name is to know who it is applied to.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], §VI)
     A reaction: Actually, you would find 'Waverley' a bit baffling too. Would you understand "he was the author of his own destruction"? You can understand "Homer was the author of this" without knowing quite who 'Homer' applies to. All very tricky.
There are a set of criteria for pinning down a logically proper name [Russell, by Sainsbury]
     Full Idea: A logically proper name must be semantically simple, have just one referent, be understood by the user, be scopeless, is not a definite description, and rigidly designates.
     From: report of Bertrand Russell (The Philosophy of Logical Atomism [1918], 24th pg) by Mark Sainsbury - The Essence of Reference Intro
     A reaction: Famously, Russell's hopes of achieving this logically desirable end got narrower and narrower, and ended with 'this' or 'that'. Maybe pure language can't do the job.
5. Theory of Logic / F. Referring in Logic / 1. Naming / b. Names as descriptive
Treat description using quantifiers, and treat proper names as descriptions [Russell, by McCullogh]
     Full Idea: Having proposed that descriptions should be treated in quantificational terms, Russell then went on to introduce the subsidiary injunction that proper names should be treated as descriptions.
     From: report of Bertrand Russell (The Philosophy of Logical Atomism [1918]) by Gregory McCullogh - The Game of the Name 2.18
     A reaction: McCulloch says Russell 'has a lot to answer for' here. It became a hot topic with Kripke. Personally I find Lewis's notion of counterparts the most promising line of enquiry.
5. Theory of Logic / F. Referring in Logic / 1. Naming / e. Empty names
A name has got to name something or it is not a name [Russell]
     Full Idea: A name has got to name something or it is not a name.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], 66th pg), quoted by Mark Sainsbury - The Essence of Reference 18.2
     A reaction: This seems to be stipulative, since most people would say that a list of potential names for a baby counted as names. It may be wrong. There are fictional names, or mistakes.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / b. Types of number
The number 3 is presumably identical as a natural, an integer, a rational, a real, and complex [Shapiro]
     Full Idea: It is surely wise to identify the positions in the natural numbers structure with their counterparts in the integer, rational, real and complex number structures.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 10.2)
     A reaction: The point is that this might be denied, since 3, 3/1, 3.00.., and -3*i^2 are all arrived at by different methods of construction. Natural 3 has a predecessor, but real 3 doesn't. I agree, intuitively, with Shapiro. Russell (1919) disagreed.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / h. Reals from Cauchy
Cauchy gave a formal definition of a converging sequence. [Shapiro]
     Full Idea: A sequence a1,a2,... of rational numbers is 'Cauchy' if for each rational number ε>0 there is a natural number N such that for all natural numbers m, n, if m>N and n>N then -ε < am - an < ε.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 7.2 n4)
     A reaction: The sequence is 'Cauchy' if N exists.
6. Mathematics / B. Foundations for Mathematics / 1. Foundations for Mathematics
Categories are the best foundation for mathematics [Shapiro]
     Full Idea: There is a dedicated contingent who hold that the category of 'categories' is the proper foundation for mathematics.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 10.3 n7)
     A reaction: He cites Lawvere (1966) and McLarty (1993), the latter presenting the view as a form of structuralism. I would say that the concept of a category will need further explication, and probably reduce to either sets or relations or properties.
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / f. Zermelo numbers
Two definitions of 3 in terms of sets disagree over whether 1 is a member of 3 [Shapiro]
     Full Idea: Zermelo said that for each number n, its successor is the singleton of n, so 3 is {{{null}}}, and 1 is not a member of 3. Von Neumann said each number n is the set of numbers less than n, so 3 is {null,{null},{null,{null}}}, and 1 is a member of 3.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 10.2)
     A reaction: See Idea 645 - Zermelo could save Plato from the criticisms of Aristotle! These two accounts are cited by opponents of the set-theoretical account of numbers, because it seems impossible to arbitrate between them.
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / a. Structuralism
Numbers do not exist independently; the essence of a number is its relations to other numbers [Shapiro]
     Full Idea: The structuralist vigorously rejects any sort of ontological independence among the natural numbers; the essence of a natural number is its relations to other natural numbers.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 10.1)
     A reaction: This seems to place the emphasis on ordinals (what order?) rather than on cardinality (how many?). I am strongly inclined to think that this is the correct view, though you can't really have relations if there is nothing to relate.
A 'system' is related objects; a 'pattern' or 'structure' abstracts the pure relations from them [Shapiro]
     Full Idea: A 'system' is a collection of objects with certain relations among them; a 'pattern' or 'structure' is the abstract form of a system, highlighting the interrelationships and ignoring any features they do not affect how they relate to other objects.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 10.1)
     A reaction: Note that 'ignoring' features is a psychological account of abstraction, which (thanks to Frege and Geach) is supposed to be taboo - but which I suspect is actually indispensable in any proper account of thought and concepts.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
Logicism seems to be a non-starter if (as is widely held) logic has no ontology of its own [Shapiro]
     Full Idea: The thesis that principles of arithmetic are derivable from the laws of logic runs against a now common view that logic itself has no ontology. There are no particular logical objects. From this perspective logicism is a non-starter.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 5.1)
     A reaction: This criticism strikes me as utterly devastating. There are two routes to go: prove that logic does have an ontology of objects (what would they be?), or - better - deny that arithmetic contains any 'objects'. Or give up logicism.
6. Mathematics / C. Sources of Mathematics / 7. Formalism
Term Formalism says mathematics is just about symbols - but real numbers have no names [Shapiro]
     Full Idea: Term Formalism is the view that mathematics is just about characters or symbols - the systems of numerals and other linguistic forms. ...This will cover integers and rational numbers, but what are real numbers supposed to be, if they lack names?
     From: Stewart Shapiro (Thinking About Mathematics [2000], 6.1.1)
     A reaction: Real numbers (such as pi and root-2) have infinite decimal expansions, so we can start naming those. We could also start giving names like 'Harry' to other reals, though it might take a while. OK, I give up.
Game Formalism is just a matter of rules, like chess - but then why is it useful in science? [Shapiro]
     Full Idea: Game Formalism likens mathematics to chess, where the 'content' of mathematics is exhausted by the rules of operating with its language. ...This, however, leaves the problem of why the mathematical games are so useful to the sciences.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 6.1.2)
     A reaction: This thought pushes us towards structuralism. It could still be a game, but one we learned from observing nature, which plays its own games. Chess is, after all, modelled on warfare.
Deductivism says mathematics is logical consequences of uninterpreted axioms [Shapiro]
     Full Idea: The Deductivist version of formalism (sometimes called 'if-thenism') says that the practice of mathematics consists of determining logical consequences of otherwise uninterpreted axioms.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 6.2)
     A reaction: [Hilbert is the source] More plausible than Term or Game Formalism (qv). It still leaves the question of why it seems applicable to nature, and why those particular axioms might be chosen. In some sense, though, it is obviously right.
6. Mathematics / C. Sources of Mathematics / 9. Fictional Mathematics
Numbers are classes of classes, and hence fictions of fictions [Russell]
     Full Idea: Numbers are classes of classes, and classes are logical fictions, so that numbers are, as it were, fictions at two removes, fictions of fictions.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], §VIII)
     A reaction: This summarises the findings of Russell and Whitehead's researches into logicism. Gödel may have proved that project impossible, but there is now debate about that. Personally I think of numbers as names of patterns.
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / b. Intuitionism
Critics resent the way intuitionism cripples mathematics, but it allows new important distinctions [Shapiro]
     Full Idea: Critics commonly complain that the intuitionist restrictions cripple the mathematician. On the other hand, intuitionist mathematics allows for many potentially important distinctions not available in classical mathematics, and is often more subtle.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 7.1)
     A reaction: The main way in which it cripples is its restriction on talk of infinity ('Cantor's heaven'), which was resented by Hilbert. Since high-level infinities are interesting, it would be odd if we were not allowed to discuss them.
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / c. Conceptualism
Conceptualist are just realists or idealist or nominalists, depending on their view of concepts [Shapiro]
     Full Idea: I classify conceptualists according to what they say about properties or concepts. If someone classified properties as existing independent of language I would classify her as a realist in ontology of mathematics. Or they may be idealists or nominalists.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 2.2.1)
     A reaction: In other words, Shapiro wants to eliminate 'conceptualist' as a useful label in philosophy of mathematics. He's probably right. All thought involves concepts, but that doesn't produce a conceptualist theory of, say, football.
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / d. Predicativism
'Impredicative' definitions refer to the thing being described [Shapiro]
     Full Idea: A definition of a mathematical entity is 'impredicative' if it refers to a collection that contains the defined entity. The definition of 'least upper bound' is impredicative as it refers to upper bounds and characterizes a member of this set.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 1.2)
     A reaction: The big question is whether mathematics can live with impredicative definitions, or whether they threaten to be viciously circular, and undermine the whole enterprise.
7. Existence / C. Structure of Existence / 6. Fundamentals / d. Logical atoms
Russell's new logical atomist was of particulars, universals and facts (not platonic propositions) [Russell, by Linsky,B]
     Full Idea: Russell's new logical atomist ontology was of particulars, universals and facts, replacing the ontology of 'platonic atomism' consisting just of propositions.
     From: report of Bertrand Russell (The Philosophy of Logical Atomism [1918]) by Bernard Linsky - Russell's Metaphysical Logic 1
     A reaction: Linsky cites Peter Hylton as saying that the earlier view was never replaced. The earlier view required propositions to be 'unified'. I surmise that the formula 'Fa' combines a universal and a particular, to form an atomic fact. [...but Idea 6111!]
Russell's atomic facts are actually compounds, and his true logical atoms are sense data [Russell, by Quine]
     Full Idea: In 1918 Russell does not admit facts as fundamental; atomic facts are atomic as facts go, but they are compound objects. The atoms of Russell's logical atomism are not atomic facts but sense data.
     From: report of Bertrand Russell (The Philosophy of Logical Atomism [1918]) by Willard Quine - Russell's Ontological Development p.83
     A reaction: By about 1921 Russell had totally given up sense-data, because he had been reading behaviourist psychology.
Logical atomism aims at logical atoms as the last residue of analysis [Russell]
     Full Idea: I call my doctrine logical atomism because, as the last residue of analysis, I wish to arrive at logical atoms and not physical atoms; some of them will be particulars, and others will be predicates and relations and so on.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], §I)
     A reaction: However we judge it, logical atomism is a vital landmark in the history of 'analytical' philosophy, because it lays out the ideal for our assessment. It is fashionable to denigrate analysis, but I think it is simply the nearest to wisdom we will ever get.
Once you have enumerated all the atomic facts, there is a further fact that those are all the facts [Russell]
     Full Idea: When you have enumerated all the atomic facts in the world, it is a further fact about the world that those are all the atomic facts there are about the world.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], §V)
     A reaction: There is obviously a potential regress of facts about facts here. This looks like one of the reasons why the original logical atomism had a short shelf-life. Personally I see this as an argument in favour of rationalism, in the way Bonjour argues for it.
Logical atoms aims to get down to ultimate simples, with their own unique reality [Russell]
     Full Idea: Logical atomism is the view that you can get down in theory, if not in practice, to ultimate simples, out of which the world is built, and that those simples have a kind of reality not belonging to anything else.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], §VIII)
     A reaction: This dream is to empiricists what the Absolute is to rationalists - a bit silly, but an embodiment of the motivating dream.
7. Existence / D. Theories of Reality / 8. Facts / a. Facts
You can't name all the facts, so they are not real, but are what propositions assert [Russell]
     Full Idea: Facts are the sort of things that are asserted or denied by propositions, and are not properly entities at all in the same sense in which their constituents are. That is shown by the fact that you cannot name them.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], p.235), quoted by Bernard Linsky - Russell's Metaphysical Logic 2.2
     A reaction: [ref to Papers vol.8] It is customary to specify a proposition by its capacity for T and F. So is a fact just 'a truth'? This contains the Fregean idea that things are only real if they can be picked out. I think of facts as independent of minds.
7. Existence / D. Theories of Reality / 8. Facts / b. Types of fact
Russell asserts atomic, existential, negative and general facts [Russell, by Armstrong]
     Full Idea: Russell argues for atomic facts, and also for existential facts, negative facts and general facts.
     From: report of Bertrand Russell (The Philosophy of Logical Atomism [1918]) by David M. Armstrong - Truth and Truthmakers 05.1
     A reaction: Armstrong says he overdoes it. I would even add disjunctive facts, which Russell rejects. 'Rain or snow will ruin the cricket match'. Rain can make that true, but it is a disjunctive fact about the match.
7. Existence / D. Theories of Reality / 9. States of Affairs
Modern trope theory tries, like logical atomism, to reduce things to elementary states [Russell, by Ellis]
     Full Idea: Russell and Wittgenstein sought to reduce everything to singular facts or states of affairs, and Armstrong and Keith Campbell have more recently advocated ontologies of tropes or elementary states of affairs.
     From: report of Bertrand Russell (The Philosophy of Logical Atomism [1918]) by Brian Ellis - The Philosophy of Nature: new essentialism Ch.3 n 11
     A reaction: A very interesting historical link. Logical atomism strikes me as a key landmark in the history of philosophy, and not an eccentric cul-de-sac. It is always worth trying to get your ontology down to minimal small units, to see what happens.
7. Existence / D. Theories of Reality / 11. Ontological Commitment / a. Ontological commitment
'Existence' means that a propositional function is sometimes true [Russell]
     Full Idea: When you take any propositional function and assert of it that it is possible, that it is sometimes true, that gives you the fundamental meaning of 'existence'.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918]), quoted by Colin McGinn - Logical Properties Ch.2
     A reaction: Functions depend on variables, so this leads to Quine's slogan "to be is to be the value of a variable". Assertions of non-existence are an obvious problem, but Russell thought of all that. All of this makes existence too dependent on language.
9. Objects / B. Unity of Objects / 2. Substance / c. Types of substance
Descartes says there are two substance, Spinoza one, and Leibniz infinitely many [Cottingham]
     Full Idea: Descartes was a dualist about substance, Spinoza was a monist, and Leibniz was a pluralist (an infinity of substances).
     From: John Cottingham (The Rationalists [1988], p.76)
     A reaction: Spinoza is appealing. We posit a substance, as the necessary basis for existence, but it is unclear how more than one substance can be differentiated. If mind is a separate substance, why isn't iron? Why aren't numbers?
10. Modality / A. Necessity / 2. Nature of Necessity
Modal terms are properties of propositional functions, not of propositions [Russell]
     Full Idea: Traditional philosophy discusses 'necessary', 'possible' and 'impossible' as properties of propositions, whereas in fact they are properties of propositional functions; propositions are only true or false.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], §V)
     A reaction: I am unclear how a truth could be known to be necessary if it is full of variables. 'x is human' seems to have no modality, but 'Socrates is human' could well be necessary. I like McGinn's rather adverbial account of modality.
12. Knowledge Sources / B. Perception / 5. Interpretation
Perception goes straight to the fact, and not through the proposition [Russell]
     Full Idea: I am inclined to think that perception, as opposed to belief, does go straight to the fact and not through the proposition.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], §IV.4)
     A reaction: There seems to be a question of an intermediate stage, which is the formulation of concepts. Is full 'perception' (backed by attention and intellect) laden with concepts, which point to facts? Where are the facts in sensation without recognition?
12. Knowledge Sources / C. Rationalism / 1. Rationalism
The notion of substance lies at the heart of rationalist metaphysics [Cottingham]
     Full Idea: The notion of substance lies at the heart of rationalist metaphysics.
     From: John Cottingham (The Rationalists [1988], p.75)
     A reaction: The idea of 'substance' has had an interesting revival in modern philosophy (though not, obviously, in physics). Maybe physics and philosophy have views of reality which are not complementary, but are rivals.
Rationalism tries to apply mathematical methodology to all of knowledge [Shapiro]
     Full Idea: Rationalism is a long-standing school that can be characterized as an attempt to extend the perceived methodology of mathematics to all of knowledge.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 1.1)
     A reaction: Sometimes called 'Descartes's Dream', or the 'Enlightenment Project', the dream of proving everything. Within maths, Hilbert's Programme aimed for the same certainty. Idea 22 is the motto for the opposition to this approach.
18. Thought / A. Modes of Thought / 6. Judgement / b. Error
The theory of error seems to need the existence of the non-existent [Russell]
     Full Idea: It is very difficult to deal with the theory of error without assuming the existence of the non-existent.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], §IV.3)
     A reaction: This problem really bothered Russell (and Plato). I suspect that it was a self-inflicted problem because at this point Russell had ceased to believe in propositions. If we accept propositions as intentional objects, they can be as silly as you like.
19. Language / C. Assigning Meanings / 3. Predicates
Russell uses 'propositional function' to refer to both predicates and to attributes [Quine on Russell]
     Full Idea: Russell used the phrase 'propositional function' (adapted from Frege) to refer sometimes to predicates and sometimes to attributes.
     From: comment on Bertrand Russell (The Philosophy of Logical Atomism [1918]) by Willard Quine - Philosophy of Logic Ch.5
     A reaction: He calls Russell 'confused' on this, and he would indeed be guilty of what now looks like a classic confusion, between the properties and the predicates that express them. Only a verificationist would hold such a daft view.
19. Language / D. Propositions / 1. Propositions
Propositions don't name facts, because each fact corresponds to a proposition and its negation [Russell]
     Full Idea: It is obvious that a proposition is not the name for a fact, from the mere circumstance that there are two propositions corresponding to each fact, one the negation of the other.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], §I)
     A reaction: Russell attributes this point to Wittgenstein. Evidently you must add that the proposition is true before it will name a fact - which is bad news for the redundancy view of truth. Couldn't lots of propositions correspond to one fact?
19. Language / D. Propositions / 3. Concrete Propositions
In 1918 still believes in nonlinguistic analogues of sentences, but he now calls them 'facts' [Russell, by Quine]
     Full Idea: In 1918 Russell insists that the world does contain nonlinguistic things that are akin to sentences and are asserted by them; he merely does not call them propositions. He calls them facts.
     From: report of Bertrand Russell (The Philosophy of Logical Atomism [1918]) by Willard Quine - Russell's Ontological Development p.81
     A reaction: Clarification! I have always been bewildered by the early Russell view of propositions as actual ingredients of the world. If we say that sentences assert facts, that makes more sense. Russell never believed in the mental entities I call 'propositions'.
19. Language / D. Propositions / 6. Propositions Critique
An inventory of the world does not need to include propositions [Russell]
     Full Idea: It is quite clear that propositions are not what you might call 'real'; if you were making an inventory of the world, propositions would not come in.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], §III)
     A reaction: I am not clear why this is "quite clear". Propositions might even turn up in our ontology as physical objects (brain states). He says beliefs are real, but if you can't have a belief without a proposition, and they aren't real, you are in trouble.
I no longer believe in propositions, especially concerning falsehoods [Russell]
     Full Idea: Time was when I thought there were propositions, but it does not seem to me very plausible to say that in addition to facts there are also these curious shadowy things going about as 'That today is Wednesday' when in fact it is Tuesday.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], §IV.2)
     A reaction: You need to give some account of someone who thinks 'Today is Wednesday' when it is Tuesday. We can hardly avoid talking about something like an 'intentional object', which can be expressed in a sentence. Are there not possible (formulable) propositions?
I know longer believe in shadowy things like 'that today is Wednesday' when it is actually Tuesday [Russell]
     Full Idea: Time was when I thought there were propositions, but it does not seem to me very plausible to say that in addition to facts there are also these curious shadowy things going about such 'That today is Wednesday' when it is in fact Tuesday.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], p.197), quoted by Bernard Linsky - Russell's Metaphysical Logic 3.1
     A reaction: [Ref to Papers v8] I take Russell to have abandoned his propositions because his conception of them was mistaken. Presumably my thinking 'Today is Wednesay' conjures up a false proposition, which had not previously existed.
19. Language / F. Communication / 4. Private Language
The names in a logically perfect language would be private, and could not be shared [Russell]
     Full Idea: A logically perfect language, if it could be constructed, would be, as regards its vocabulary, very largely private to one speaker; that is, all the names in it would be private to that speaker and could not enter into the language of another speaker.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], §II)
     A reaction: Wittgenstein obviously thought there was something not quite right about this… See Idea 4147, for example. I presume Russell's thought is that you would have no means of explaining the 'meanings' of the names in the language.
26. Natural Theory / C. Causation / 9. General Causation / d. Causal necessity
For rationalists, it is necessary that effects be deducible from their causes [Cottingham]
     Full Idea: The rationalist view of causation takes it that to make effects intelligible, it must be shown that they are in principle deducible from their causes.
     From: John Cottingham (The Rationalists [1988], p.92)
     A reaction: This has intuitive appeal, but deduction is only possible with further premises, such as the laws of physics. The effects of human behaviour look a bit tricky, even if we cause them.
28. God / B. Proving God / 2. Proofs of Reason / b. Ontological Proof critique
You can discuss 'God exists', so 'God' is a description, not a name [Russell]
     Full Idea: The fact that you can discuss the proposition 'God exists' is a proof that 'God', as used in that proposition, is a description and not a name. If 'God' were a name, no question as to its existence could arise.
     From: Bertrand Russell (The Philosophy of Logical Atomism [1918], §VI)
     A reaction: Presumably 'a being than which none greater can be conceived' (Anselm's definition) is self-evidently a description, and doesn't claim to be a name. Aquinas caps each argument with a triumphant naming of the being he has proved.