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All the ideas for 'Thinking About Mathematics', 'The Principles of Human Knowledge' and 'The Ultimate Constituents of Matter'

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57 ideas

3. Truth / C. Correspondence Truth / 3. Correspondence Truth critique
An idea can only be like another idea [Berkeley]
     Full Idea: An idea can be like nothing but an idea.
     From: George Berkeley (The Principles of Human Knowledge [1710], §08), quoted by Michael Potter - The Rise of Analytic Philosophy 1879-1930 43 'Mean'
     A reaction: I take this to be relevant to the correspondence theory, but also to be one of Berkeley's best observations. We understand ideas, but we can't map them onto the world (because they are not maps!). ...But then how is one idea like another? Hm.
4. Formal Logic / F. Set Theory ST / 8. Critique of Set Theory
Classes, grouped by a convenient property, are logical constructions [Russell]
     Full Idea: Classes or series of particulars, collected together on account of some property which makes it convenient to be able to speak of them as wholes, are what I call logical constructions or symbolic fictions.
     From: Bertrand Russell (The Ultimate Constituents of Matter [1915], p.125)
     A reaction: When does a construction become 'logical' instead of arbitrary? What is it about a property that makes it 'convenient'? At this point Russell seems to have built his ontology on classes, and the edifice was crumbling, thanks to Wittgenstein.
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.
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 / 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 / A. Nature of Existence / 4. Abstract Existence
Abstract ideas are impossible [Berkeley]
     Full Idea: We have, I think, shown the impossibility of Abstract Ideas.
     From: George Berkeley (The Principles of Human Knowledge [1710], Intro §21)
     A reaction: He achieves this by an attack on universals, offering the nominalist view that there are only particulars. There seems to be a middle ground, where universals don't actually exist, but there are settled conventional abstraction, beyond particulars.
7. Existence / D. Theories of Reality / 4. Anti-realism
Visible things are physical and external, but only exist when viewed [Russell]
     Full Idea: I believe that common sense is right in regarding what we see as physical and (in one of several possible senses) outside the mind, but is probably wrong in supposing that it continues to exist when we are no longer looking at it.
     From: Bertrand Russell (The Ultimate Constituents of Matter [1915], p.123)
     A reaction: This remark (in 1915) is a bit startling from a philosopher well known for his robustly realist stance. Just one of his phases! It seems very counterintuitive - that objects really exist externally, but only when viewed. Schrödinger's Cat?
Berkeley does believe in trees, but is confused about what trees are [Berkeley, by Cameron]
     Full Idea: I think that we should consider Berkeley as believing in trees; we should simply claim that he has false beliefs about what trees are.
     From: report of George Berkeley (The Principles of Human Knowledge [1710]) by Ross P. Cameron - Truthmakers, Realism and Ontology 'Realism'
     A reaction: I can be realist about spots before my eyes, or a ringing in my ears, but be (quite sensibly) unsure about what they are, so Cameron's suggestion sounds plausible.
8. Modes of Existence / E. Nominalism / 1. Nominalism / b. Nominalism about universals
Universals do not have single meaning, but attach to many different particulars [Berkeley]
     Full Idea: There is no such thing as one precise and definite signification annexed to any general name, they all signifying indifferently a great number of particular ideas.
     From: George Berkeley (The Principles of Human Knowledge [1710], Intro §18)
     A reaction: The term 'red' may be assigned to a range of colours, but we also recognise the precision of 'that red'. For 'electron', or 'three', or 'straight', the particulars are indistinguishable.
No one will think of abstractions if they only have particular ideas [Berkeley]
     Full Idea: He that knows he has no other than particular ideas, will not puzzle himself in vain to find out and conceive the abstract idea annexed to any name.
     From: George Berkeley (The Principles of Human Knowledge [1710], Intro §24)
     A reaction: A nice point against universals. Maybe gods only think in particulars. One particular on its own could never suggest a universal. How are you going to spot patterns if you don't think in universals? Maths needs patterns.
8. Modes of Existence / E. Nominalism / 2. Resemblance Nominalism
Universals do not have any intrinsic properties, but only relations to particulars [Berkeley]
     Full Idea: Universality, so far as I can comprehend it, does not consist in the absolute, positive nature or conception of anything, but in the relation it bears to the particulars signified or represented by it.
     From: George Berkeley (The Principles of Human Knowledge [1710], Intro §15)
     A reaction: I always think it is a basic principle in philosophy that some sort of essence must precede relations (and functions). What is it about universals that enables them to have a relation to particulars?
9. Objects / B. Unity of Objects / 2. Substance / d. Substance defined
Material substance is just general existence which can have properties [Berkeley]
     Full Idea: The most accurate philosophers have no other meaning annexed to 'material substance' but the idea of being in general, together with the relative notion of its supporting accidents.
     From: George Berkeley (The Principles of Human Knowledge [1710], §17)
     A reaction: This is part of the attack on Aristotle's concept of 'substance', and is a nice way of dissolving the concept. 'Substance' will never reappear in physics, but modern philosopher have returned to it, as possibly inescapable in metaphysics.
9. Objects / B. Unity of Objects / 2. Substance / e. Substance critique
A die has no distinct subject, but is merely a name for its modes or accidents [Berkeley]
     Full Idea: To me a die seems to be nothing distinct from those things which are termed its modes or accidents. And to say a die is hard, extended and square is not to attribute those qualities to a distinct subject, but only an explication of the word 'die'.
     From: George Berkeley (The Principles of Human Knowledge [1710], n 49)
     A reaction: This is apparently a reaction to Locke, and a final rejection of the medieval idea of a 'substance'. Unfortunately it leaves Berkeley with a 'bundle' view of objects (a typical empiricist account), which is even worse.
11. Knowledge Aims / C. Knowing Reality / 2. Phenomenalism
Perception is existence for my table, but also possible perception, by me or a spirit [Berkeley]
     Full Idea: The table I write on I say exists, that is, I see and feel it; and if I were out of my study I should say it existed - meaning thereby that if I was in my study I might perceive it, or that some other spirit actually does perceive it.
     From: George Berkeley (The Principles of Human Knowledge [1710], §3)
     A reaction: Berkeley is always (understandably) labelled as an 'idealist', but this seems to be what we call 'phenomenalism', because it allows possible experiences as well as actual ones. See Ideas 5170 and 6522.
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / c. Empirical idealism
The only substance is spirit, or that which perceives [Berkeley]
     Full Idea: It is evident that there is not any other Substance than spirit, or that which perceives.
     From: George Berkeley (The Principles of Human Knowledge [1710], §7)
     A reaction: Weird. To say that this is 'evident' seems to be begging the question. Why should he assume that there is nothing more to reality than his perception of it? He seems strangely unimaginative.
The 'esse' of objects is 'percipi', and they can only exist in minds [Berkeley]
     Full Idea: The absolute existence of unthinking things with no relation to their being perceived is unintelligible to me; their 'esse' is 'percipi', nor is it possible they should have any existence out of the minds or thinking things which perceive them.
     From: George Berkeley (The Principles of Human Knowledge [1710], §3)
     A reaction: "Esse est percipi" (to be is to be perceived) is the well-known slogan associated with Berkeley. I cannot see how Berkeley can assert that the separate existence of things is impossible. He is the classic confuser of epistemology and ontology.
When I shut my eyes, the things I saw may still exist, but in another mind [Berkeley]
     Full Idea: When I shut my eyes, the things I saw may still exist, but it must be in another mind.
     From: George Berkeley (The Principles of Human Knowledge [1710], §90)
     A reaction: This strikes me as ridiculous. What kind of theory says that a table goes out of existence when someone forgets to look at it for a moment, but is then recreated in identical form? Epistemology is not ontology.
12. Knowledge Sources / B. Perception / 2. Qualities in Perception / e. Primary/secondary critique
No one can, by abstraction, conceive extension and motion of bodies without sensible qualities [Berkeley]
     Full Idea: I desire any one to reflect and try whether he can, by any abstraction of thought, conceive the extension and motion of a body without any sensible qualities.
     From: George Berkeley (The Principles of Human Knowledge [1710], §10)
     A reaction: The rather geometrical view of objects found in Descartes and Russell is an attempt to do this. I don't think the fact that we can't really achieve it matters much. We divide primary from secondary qualities in our understanding, not in experience.
Motion is in the mind, since swifter ideas produce an appearance of slower motion [Berkeley]
     Full Idea: Is it not reasonable to say that motion is not without the mind, since if the succession of ideas in the mind become swifter the motion, it is acknowledged, shall appear slower without any alteration in any external object.
     From: George Berkeley (The Principles of Human Knowledge [1710], §14)
     A reaction: An intriguing argument, based on what is now the principle of slow-motion photography. Fast minds slow down movement, like great tennis players. By what right does Berkeley say that the external subject is unaltered?
Figure and extension seem just as dependent on the observer as heat and cold [Berkeley]
     Full Idea: If heat and cold are only affections of the mind (since the same body seems cold to one hand and warm to the other), why may we not argue that figure and extension also appear different to the same eye at different stations?
     From: George Berkeley (The Principles of Human Knowledge [1710], §14)
     A reaction: If the assessment of the qualities of an object is entirely a matter of our experiences of it, there is no denying Berkeley on this. However, judgement goes beyond experience, into speculations, inferences, and explanations.
12. Knowledge Sources / B. Perception / 3. Representation
Berkeley's idealism resulted from fear of scepticism in representative realism [Robinson,H on Berkeley]
     Full Idea: It was fear of scepticism based upon representative realism that motivated Berkeley's idealism.
     From: comment on George Berkeley (The Principles of Human Knowledge [1710]) by Howard Robinson - Perception II.1
     A reaction: Personally I side with Russell, who accepts representative realism, and also accepts that some degree of scepticism is unavoidable, but without getting excited about it. The key to everything is to be a 'fallibilist' about knowledge.
12. Knowledge Sources / B. Perception / 4. Sense Data / b. Nature of sense-data
If my body literally lost its mind, the object seen when I see a flash would still exist [Russell]
     Full Idea: My meaning may be made plainer by saying that if my body could remain in exactly the same state in which it is, though my mind had ceased to exist, precisely that object which I now see when I see a flash would exist, though I should not see it.
     From: Bertrand Russell (The Ultimate Constituents of Matter [1915], p.126)
     A reaction: Zombies, 70 years before Robert Kirk! Sense-data are physical. It is interesting to see a philosopher as committed to empiricism, anti-spiritualism and the priority of science as this, still presenting an essentially dualist picture of perception.
Sense-data are purely physical [Russell]
     Full Idea: Sense-data are purely physical, and all that is mental in connection with them is our awareness of them.
     From: Bertrand Russell (The Ultimate Constituents of Matter [1915], p.138)
     A reaction: Once this account of sense-data becomes fully clear, it also becomes apparent what a dualist theory it is. The mind is a cinema, I am the audience, and sense-data are the screen. There has to be a big logical gap between viewer and screen.
12. Knowledge Sources / C. Rationalism / 1. Rationalism
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.
12. Knowledge Sources / D. Empiricism / 1. Empiricism
Knowledge is of ideas from senses, or ideas of the mind, or operations on sensations [Berkeley]
     Full Idea: The objects of knowledge are either ideas imprinted on the senses, or passions and operations of the mind, or ideas (formed by memory and imagination) compounding, dividing or barely representing the original perceptions.
     From: George Berkeley (The Principles of Human Knowledge [1710], §1)
     A reaction: This is the germ of Hume's 'associations' (Idea 2189). There is not much room here for synthetic a priori knowledge, as the a priori part seems to merely know the mind. Most of Russell's epistemology is contained in the last part of the sentence.
15. Nature of Minds / A. Nature of Mind / 4. Other Minds / a. Other minds
Berkeley's idealism gives no grounds for believing in other minds [Reid on Berkeley]
     Full Idea: I can find no principle in Berkeley's system, which affords me even probable ground to conclude that there are other intelligent beings, like myself.
     From: comment on George Berkeley (The Principles of Human Knowledge [1710]) by Thomas Reid - Essays on Intellectual Powers 2: Senses 10
     A reaction: I agree, which means that Berkeley's position seems to entail solipsism, unless God is the Cartesian deus ex machina who rescues him from this wall of ignorance.
15. Nature of Minds / A. Nature of Mind / 4. Other Minds / c. Knowing other minds
I know other minds by ideas which are referred by me to other agents, as their effects [Berkeley]
     Full Idea: The knowledge I have of other spirits is not immediate, as is the knowledge of my ideas; but depending on the intervention of ideas, by me referred to agents or spirits distinct from myself, as effects or concomitant signs.
     From: George Berkeley (The Principles of Human Knowledge [1710], §145)
     A reaction: This strikes me as gross intellectual dishonesty, since the argument Berkeley uses to assert other minds could equally be used to assert the existence of tables ('by me referred to agents distinct from myself, as effects'). Be a solipsist or a realist.
15. Nature of Minds / A. Nature of Mind / 7. Animal Minds
If animals have ideas, and are not machines, they must have some reason [Berkeley]
     Full Idea: If the brutes have any ideas at all, and are not bare machines (as some would have them), we cannot deny them to have some reason.
     From: George Berkeley (The Principles of Human Knowledge [1710], Intro §11)
     A reaction: It seems possible to imagine a low level of mind, where a few ideas (or concepts) float around, but hardly anything worth the name of reason. However, a Darwinian view suggests that concepts must bestow an advantage, so the two go together.
15. Nature of Minds / B. Features of Minds / 4. Intentionality / b. Intentionality theories
Berkeley replaced intentionality with an anti-abstractionist imagist theory of thought [Berkeley, by Robinson,H]
     Full Idea: By Berkeley - with his anti-abstractionism and imagist theory of thought - the classical sense-datum conception was firmly established, and intentionality had disappeared as an intrinsic property, not only of perceptual states, but of all mental contents.
     From: report of George Berkeley (The Principles of Human Knowledge [1710]) by Howard Robinson - Perception 1.6
     A reaction: Intentionality was originally a medieval concept, and was revived by Brentano in the late nineteenth century. Nowadays intentionality is taken for granted, but I still suspect that we could drop it, and talk of nothing but brain states caused by reality.
15. Nature of Minds / C. Capacities of Minds / 3. Abstraction by mind
The mind creates abstract ideas by considering qualities separated from their objects [Berkeley]
     Full Idea: We are told that the mind being able to consider each quality of things singly, or abstracted from those other qualities with which it is united, does by that means frame to itself abstract ideas.
     From: George Berkeley (The Principles of Human Knowledge [1710], Intro §7)
     A reaction: A helpful explanation of 'abstract' ideas. Berkeley gives colour and movement as examples. Fodor suggests that abstraction is the key strategy in empiricist epistemology. The difficulty is to decide whether the qualities are natural or conventional.
I can only combine particulars in imagination; I can't create 'abstract' ideas [Berkeley]
     Full Idea: Whether others can abstract their ideas, they best can tell. For myself, I find I have a faculty of imagining, or representing to myself, only the idea of those particular things I have perceived, and of compounding and dividing them.
     From: George Berkeley (The Principles of Human Knowledge [1710], 10)
     A reaction: He is admitting mixing experiences, but always particulars, never abstract. His examples are 'man' and 'motion'. Compare Aristotle Idea 9067. Berkeley is, I think, trapped in a false imagistic view of thought. My image of Plato blurs young and old.
16. Persons / D. Continuity of the Self / 2. Mental Continuity / b. Self as mental continuity
A man is a succession of momentary men, bound by continuity and causation [Russell]
     Full Idea: The real man, I believe, however the police may swear to his identity, is really a series of momentary men, each different one from the other, and bound together, not by a numerical identity, but by continuity and certain instrinsic causal laws.
     From: Bertrand Russell (The Ultimate Constituents of Matter [1915], p.124)
     A reaction: This seems to be in the tradition of Locke and Parfit, and also follows the temporal-slices idea of physical objects. Personally I take a more physical view of things, and think the police are probably more reliable than Bertrand Russell.
16. Persons / D. Continuity of the Self / 7. Self and Thinking
Ideas are perceived by the mind, soul or self [Berkeley]
     Full Idea: The thing which knows or perceives ideas is what I call mind, spirit, soul or myself.
     From: George Berkeley (The Principles of Human Knowledge [1710], §2)
     A reaction: The interest here is in making no distinction between 'mind' and 'self', which seems to ally Berkeley with Locke's view of personal identity, as continuity of consciousness. The addition of 'soul' tries to connect Locke to Christian thought.
17. Mind and Body / E. Mind as Physical / 2. Reduction of Mind
We could probably, in principle, infer minds from brains, and brains from minds [Russell]
     Full Idea: It seems not improbable that if we had sufficient knowledge we could infer the state of a man's mind from the state of his brain, or the state of his brain from the state of his mind.
     From: Bertrand Russell (The Ultimate Constituents of Matter [1915], p.131)
     A reaction: This strikes me as being a very good summary of the claim that mind is reducible to brain, which is the essence of physicalism. Had he been born a little later, Russell would have taken a harder line with physicalism.
19. Language / A. Nature of Meaning / 2. Meaning as Mental
Language is presumably for communication, and names stand for ideas [Berkeley]
     Full Idea: It is a received opinion that language has no other end but the communicating our ideas, and that every significant name stands for an idea.
     From: George Berkeley (The Principles of Human Knowledge [1710], Intro §19)
     A reaction: This attitude to language has been widely discredited, partly by the observation that 'idea' is very ambiguous, and partly by the fans of meaning-as-use. Truth conditions seem to be ideas, and so are speaker's intentions.
19. Language / D. Propositions / 4. Mental Propositions
I can't really go wrong if I stick to wordless thought [Berkeley]
     Full Idea: So long as I confine my thoughts to my own ideas divested of words, I do not see how I can easily be mistaken.
     From: George Berkeley (The Principles of Human Knowledge [1710], Intro §22)
     A reaction: I think it was one of the great errors of twentieth century philosophy to say that Berkeley cannot do this, because thought needs language. Personally I think language lags along behind most our thinking, tidying up the mess. I believe in propositions.
26. Natural Theory / A. Speculations on Nature / 7. Later Matter Theories / a. Early Modern matter
No one can explain how matter affects mind, so matter is redundant in philosophy [Berkeley]
     Full Idea: How matter should operate on a spirit, or produce any idea in it, is what no philosopher will pretend to explain; it is therefore evident there can be no use of matter in natural philosophy.
     From: George Berkeley (The Principles of Human Knowledge [1710], §50)
     A reaction: An intriguing argument for idealism, which starts in Cartesian dualism, but then discards the physical world because of the notorious interaction problem. Of course, if he had thought that matter and spirit were one (Spinoza) the problem vanishes.
26. Natural Theory / C. Causation / 9. General Causation / a. Constant conjunction
We discover natural behaviour by observing settled laws of nature, not necessary connections [Berkeley]
     Full Idea: That food nourishes, sleep refreshes, and fire warms us; all this we know, not by discovering any necessary connexion between our ideas, but only by the observation of the settled laws of nature.
     From: George Berkeley (The Principles of Human Knowledge [1710], §31)
     A reaction: Hume is famous for this idea, but it is found in Hobbes too (Idea 2364), and is the standard empiricist view of causation. The word 'settled' I take to imply that the laws are contingent, because they could become unsettled at any time.
26. Natural Theory / D. Laws of Nature / 4. Regularities / a. Regularity theory
The laws of nature are mental regularities which we learn by experience [Berkeley]
     Full Idea: The set rules or established methods wherein the Mind we depend on excites in us the ideas of sense, are called the 'laws of nature'; and these we learn by experience, which teaches us that such and such ideas are attended with certain other ideas.
     From: George Berkeley (The Principles of Human Knowledge [1710], 33)
     A reaction: He observes that the ideas of sense are more regular than other mental events, and attributes the rules to an Author. He is giving the standard empirical Humean view, with his own quirky idealist slant.
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / e. Anti scientific essentialism
If properties and qualities arise from an inward essence, we will remain ignorant of nature [Berkeley]
     Full Idea: An inducement to pronouncing ourselves ignorant of the nature of things is the opinion that everything includes within itself the cause of its properties; or that there is in each object an inward essence which is the source whence its qualities flow.
     From: George Berkeley (The Principles of Human Knowledge [1710], §102)
     A reaction: This remains a good objection to essentialism - that while it remains quite a plausible picture of how nature operates, it makes the task of understanding nature hopeless. We can grasp imposed regular laws, but not secret inner essences.
27. Natural Reality / B. Modern Physics / 1. Relativity / a. Special relativity
All motion is relative, so a single body cannot move [Berkeley]
     Full Idea: There cannot be any motion other than relative; …if there was one only body in being it could not possibly move.
     From: George Berkeley (The Principles of Human Knowledge [1710], §112)
     A reaction: This seems to agree with with Leibniz in denying the Newton-Clarke idea of absolute space. See Idea 2100. Suppose there were two bodies racing towards one another, when one of them suddenly vanished?
27. Natural Reality / B. Modern Physics / 4. Standard Model / a. Concept of matter
Matter is a logical construction [Russell]
     Full Idea: We must regard matter as a logical construction.
     From: Bertrand Russell (The Ultimate Constituents of Matter [1915], p.132)
     A reaction: A logical construction is a fancy way of saying a best explanation (but with Ockham's Razor hanging over it). A key component missing from Russell's account is that we can directly experience matter, because we are made of it.
Matter requires a division into time-corpuscles as well as space-corpuscles [Russell]
     Full Idea: A true theory of matter requires a division of things into time-corpuscles as well as space-corpuscles.
     From: Bertrand Russell (The Ultimate Constituents of Matter [1915], p.125)
     A reaction: The division of matter in space seems decidable by physicists, but the division in time seems a bit arbitrary (unless it is quanta of time?). Russell focuses on observable qualities, but are there also intrinsic qualities?
27. Natural Reality / C. Space / 2. Space
Six dimensions are needed for a particular, three within its own space, and three to locate that space [Russell]
     Full Idea: The world of particulars is a six-dimensional space, where six co-ordinates will be required to assign the position of any particular, three to assign its position in its own space, and three to assign the position of its space among the other spaces.
     From: Bertrand Russell (The Ultimate Constituents of Matter [1915], p.134)
     A reaction: Not a proposal that has caught on. One might connect the idea with the notion of 'frames of reference' in Einstein's Special Theory. Inside a frame of reference, three co-ordinates are needed; but where is the frame of reference?
27. Natural Reality / D. Time / 1. Nature of Time / c. Idealist time
I cannot imagine time apart from the flow of ideas in my mind [Berkeley]
     Full Idea: Whenever I attempt to frame a simple idea of time, abstracted from the succession of ideas in my mind, which flows uniformly and is participated in by all beings, I am lost and embrangled in inextricable difficulties.
     From: George Berkeley (The Principles of Human Knowledge [1710], §98)
     A reaction: 'Embrangled'! A nice statement of the idealist view of time, as entirely mental. I know what he means. However, surely he can manage to imagine a movement which continues when he shuts he eyes? Try blinking during a horse race.
29. Religion / D. Religious Issues / 3. Problem of Evil / a. Problem of Evil
Particular evils are really good when linked to the whole system of beings [Berkeley]
     Full Idea: Those particular things which, considered in themselves, appear to be evil, have the nature of good, when considered as linked with the whole system of beings.
     From: George Berkeley (The Principles of Human Knowledge [1710], §153)
     A reaction: This wildly contradicts the rest of Berkeley's philosophy, which is strictly empiricist, and rests wholly on actual experience. What experience does he have of the 'whole system of beings', and its making evil into actual good?