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All the ideas for 'Mathematical Methods in Philosophy', 'Externalism' and 'The Philosophy of Logic'

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28 ideas

1. Philosophy / H. Continental Philosophy / 4. Linguistic Structuralism
Structuralism is neo-Kantian idealism, with language playing the role of categories of understanding [Rowlands]
     Full Idea: Structuralism is a form of neo-Kantian idealism, in which the job of creating Kant's phenomenal world has been taken over by language instead of forms of sensibility and categories of the understanding.
     From: Mark Rowlands (Externalism [2003], Ch.3)
     A reaction: A helpful connection, which explains my aversion to any attempt at understanding the world simply by analysing language, either in its ordinary usage, or in its underlying logical form.
5. Theory of Logic / A. Overview of Logic / 9. Philosophical Logic
Three stages of philosophical logic: syntactic (1905-55), possible worlds (1963-85), widening (1990-) [Horsten/Pettigrew]
     Full Idea: Three periods can be distinguished in philosophical logic: the syntactic stage, from Russell's definite descriptions to the 1950s, the dominance of possible world semantics from the 50s to 80s, and a current widening of the subject.
     From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 1)
     A reaction: [compressed] I've read elsewhere that the arrival of Tarski's account of truth in 1933, taking things beyond the syntactic, was also a landmark.
5. Theory of Logic / D. Assumptions for Logic / 1. Bivalence
If bivalence is rejected, then excluded middle must also be rejected [Rowlands]
     Full Idea: If you reject the principle of bivalence (that a proposition is either determinately true or false), then statements are also not subject to the Law of Excluded Middle (P or not-P).
     From: Mark Rowlands (Externalism [2003], Ch.3)
     A reaction: I think Rowlands is wrong about this. Excluded Middle could be purely syntacti, or its semantics could be 'True or Not-True'. Only bivalent excluded middle introduces 'True or False'. Compare Idea 4752.
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
Logical formalization makes concepts precise, and also shows their interrelation [Horsten/Pettigrew]
     Full Idea: Logical formalization forces the investigator to make the central philosophical concepts precise. It can also show how some philosophical concepts and objects can be defined in terms of others.
     From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 2)
     A reaction: This is the main rationale of the highly formal and mathematical approach to such things. The downside is when you impose 'precision' on language that was never intended to be precise.
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
Models are sets with functions and relations, and truth built up from the components [Horsten/Pettigrew]
     Full Idea: A (logical) model is a set with functions and relations defined on it that specify the denotation of the non-logical vocabulary. A series of recursive clauses explicate how truth values of complex sentences are compositionally determined from the parts.
     From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3)
     A reaction: See the ideas on 'Functions in logic' and 'Relations in logic' (in the alphabetical list) to expand this important idea.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / i. Cardinal infinity
Very large sets should be studied in an 'if-then' spirit [Putnam]
     Full Idea: Sets of a very high type or very high cardinality (higher than the continuum, for example), should today be investigated in an 'if-then' spirit.
     From: Hilary Putnam (The Philosophy of Logic [1971], p.347), quoted by Penelope Maddy - Naturalism in Mathematics
     A reaction: Quine says the large sets should be regarded as 'uninterpreted'.
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / b. Indispensability of mathematics
Indispensability strongly supports predicative sets, and somewhat supports impredicative sets [Putnam]
     Full Idea: We may say that indispensability is a pretty strong argument for the existence of at least predicative sets, and a pretty strong, but not as strong, argument for the existence of impredicative sets.
     From: Hilary Putnam (The Philosophy of Logic [1971], p.346), quoted by Penelope Maddy - Naturalism in Mathematics II.2
We must quantify over numbers for science; but that commits us to their existence [Putnam]
     Full Idea: Quantification over mathematical entities is indispensable for science..., therefore we should accept such quantification; but this commits us to accepting the existence of the mathematical entities in question.
     From: Hilary Putnam (The Philosophy of Logic [1971], p.57), quoted by Stephen Yablo - Apriority and Existence
     A reaction: I'm not surprised that Hartry Field launched his Fictionalist view of mathematics in response to such a counterintuitive claim. I take it we use numbers to slice up reality the way we use latitude to slice up the globe. No commitment to lines!
7. Existence / A. Nature of Existence / 1. Nature of Existence
If 'exist' doesn't express a property, we can hardly ask for its essence [Horsten/Pettigrew]
     Full Idea: If there is indeed no property of existence that is expressed by the word 'exist', then it makes no sense to ask for its essence.
     From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 2)
     A reaction: As far as I can tell, this was exactly Aristotle's conclusion, so he skirted round the question of 'being qua being', and focused on the nature of objects instead. Grand continental talk of 'Being' doesn't sound very interesting.
7. Existence / C. Structure of Existence / 5. Supervenience / a. Nature of supervenience
Supervenience is a one-way relation of dependence or determination between properties [Rowlands]
     Full Idea: Supervenience is essentially a one-way relation of dependence or determination, …which holds, in the first instance, between properties.
     From: Mark Rowlands (Externalism [2003], Ch.2)
     A reaction: This definition immediately shows why supervenient properties are in danger of being epiphenomenal (i.e. causally irrelevant). Carefully thought about the notion of a 'one-way' relation will, I think, make it more obscure rather than clearer.
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
It is argued that wholes possess modal and counterfactual properties that parts lack [Rowlands]
     Full Idea: Some have argued that a mereological whole should not be identified with the sum of its parts on the grounds that the former possess certain properties - specifically modal and (perhaps) counterfactual properties - that the latter lacks.
     From: Mark Rowlands (Externalism [2003], Ch.2)
     A reaction: I am not convinced that modal and counterfactual claims should count as properties. If my pen is heated it melts (a property), but if my pen were intelligent it could do philosophy. Intelligence is a property, but the situation isn't.
9. Objects / F. Identity among Objects / 4. Type Identity
Tokens are dated, concrete particulars; types are their general properties or kinds [Rowlands]
     Full Idea: Tokens are dated, concrete, particular occurrences or instances; types are the general properties that these occurrences exemplify or the kinds to which they belong.
     From: Mark Rowlands (Externalism [2003], Ch.2)
     A reaction: It might be said that types are sets, of which tokens are the members. The question of 'general properties' raises the question of whether universals must exist to make kinds possible.
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
A Tarskian model can be seen as a possible state of affairs [Horsten/Pettigrew]
     Full Idea: A Tarskian model can in a sense be seen as a model of a possible state of affairs.
     From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3)
     A reaction: I include this remark to show how possible worlds semantics built on the arrival of model theory.
The 'spheres model' was added to possible worlds, to cope with counterfactuals [Horsten/Pettigrew]
     Full Idea: The notion of a possible worlds model was extended (resulting in the concept of a 'spheres model') in order to obtain a satisfactory logical treatment of counterfactual conditional sentences.
     From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 4)
     A reaction: Thus we add 'centred' worlds, and an 'actual' world, to the loose original model. It is important to remember when we discuss 'close' worlds that we are then committed to these presuppositions.
10. Modality / E. Possible worlds / 1. Possible Worlds / b. Impossible worlds
Epistemic logic introduced impossible worlds [Horsten/Pettigrew]
     Full Idea: The idea of 'impossible worlds' was introduced into epistemic logic.
     From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 4)
     A reaction: Nathan Salmon seems interested in their role in metaphysics (presumably in relation to Meinongian impossible objects, like circular squares, which must necessarily be circular).
10. Modality / E. Possible worlds / 1. Possible Worlds / e. Against possible worlds
Possible worlds models contain sets of possible worlds; this is a large metaphysical commitment [Horsten/Pettigrew]
     Full Idea: Each possible worlds model contains a set of possible worlds. For this reason, possible worlds semantics is often charged with smuggling in heavy metaphysical commitments.
     From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3)
     A reaction: To a beginner it looks very odd that you should try to explain possibility by constructing a model of it in terms of 'possible' worlds.
Using possible worlds for knowledge and morality may be a step too far [Horsten/Pettigrew]
     Full Idea: When the possible worlds semantics were further extended to model notions of knowledge and of moral obligation, the application was beginning to look distinctly forced and artificial.
     From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 5)
     A reaction: They accept lots of successes in modelling necessity and time.
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / a. Idealism
Strong idealism is the sort of mess produced by a Cartesian separation of mind and world [Rowlands]
     Full Idea: Neo-Kantian idealism, and the excesses of recent versions of it, are precisely the sort of mess one can get oneself into through an uncritical acceptance of the dichotomizing of mind and world along Cartesian internalist lines.
     From: Mark Rowlands (Externalism [2003], Ch.3)
     A reaction: I am unconvinced that internalism about the mind (that its contents can be defined without reference to anything external) leads to this disastrous split. We don't have to abandon the links between an internal mind and the world.
15. Nature of Minds / A. Nature of Mind / 1. Mind / c. Features of mind
Minds are rational, conscious, subjective, self-knowing, free, meaningful and self-aware [Rowlands]
     Full Idea: The apparent features of mind which are not obviously physical include: rationality, thought, consciousness, subjectivity, infallible first-person knowledge, freedom, meaning and self-awareness.
     From: Mark Rowlands (Externalism [2003], Ch.2)
     A reaction: A helpful list, some of which can be challenged. Ryle challenges first-person infallibility. Hume challenges self-awareness. Quine challenges meaning. Lots of people (e.g. Spinoza) challenge freedom. The Churchlands seem to challenge consciousness.
15. Nature of Minds / A. Nature of Mind / 6. Anti-Individualism
Content externalism implies that we do not have privileged access to our own minds [Rowlands]
     Full Idea: Content externalism threatens the idea of first-person authority in all its forms, and does so because it calls into question the idea that the access we have to our own mental states is privileged in the way required for such authority.
     From: Mark Rowlands (Externalism [2003], Ch.7)
     A reaction: I am inclined to respond by saying that since we clearly have privileged access to our own minds, that means there must be something wrong with content externalism.
If someone is secretly transported to Twin Earth, others know their thoughts better than they do [Rowlands]
     Full Idea: If someone knew that a thinker had, without realising it, been transported to Twin Earth, they would almost certainly be a higher authority on the content of the thinker's thoughts than would the thinker.
     From: Mark Rowlands (Externalism [2003], Ch.8)
     A reaction: They would certainly be a higher authority on the truth of the thinker's thoughts, but only in the way that you might think I hold a diamond when I know it is a club. If the thinker believes it is H2O, the fact that it isn't is irrelevant to content.
17. Mind and Body / D. Property Dualism / 5. Supervenience of mind
Supervenience of mental and physical properties often comes with token-identity of mental and physical particulars [Rowlands]
     Full Idea: One often finds a supervenience thesis concerning the relation between mental and physical properties combined with a token identity theory concerning the relation between mental and physical particulars.
     From: Mark Rowlands (Externalism [2003], Ch.2)
     A reaction: This brings out the important clarifying point that supervenience is said to be between properties, not substances. The point is that supervenience will always cry out for an explanation, preferably a sensible one.
18. Thought / C. Content / 1. Content
The content of a thought is just the meaning of a sentence [Rowlands]
     Full Idea: The content of the thought that the sky is blue is simply the meaning of the sentence "The sky is blue".
     From: Mark Rowlands (Externalism [2003], Ch.5)
     A reaction: This seems to imply that it is logically impossible for a non-language-speaker, such as a chimpanzee, to think that the sky is the same colour as the water. If we allow propositions, we might be able to keep meanings without the sentences.
20. Action / A. Definition of Action / 4. Action as Movement
Action is bodily movement caused by intentional states [Rowlands]
     Full Idea: An action is a bodily movement that is caused by intentional states such as beliefs, desires and so on.
     From: Mark Rowlands (Externalism [2003], Ch.5)
     A reaction: A useful definition, and clearly one that has no truck with attempts at giving behaviourist definitions of action. The definition of a 'moral action' needs to be built on this one. Particular types of belief and desire, presumably.
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / c. Ethical intuitionism
Moral intuition seems unevenly distributed between people [Rowlands]
     Full Idea: The faculty of moral intuition seems to be unevenly distributed between people.
     From: Mark Rowlands (Externalism [2003], Ch.11)
     A reaction: This would be a good argument if it was thought that the source of moral intuitions was divine, but people vary enormously in their intuitions about maths, about character, about danger. If you believe in any intuition at all, you must accept its variety.
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / g. Atomism
The 17th century reintroduced atoms as mathematical modes of Euclidean space [Rowlands]
     Full Idea: The seventeenth century revolution reintroduced the classical concept of the atom in somewhat new attire as an essentially mathematical entity whose primary qualities could be precisely quantified as modes or aspects of Euclidean space.
     From: Mark Rowlands (Externalism [2003], Ch.2)
     A reaction: Obviously this very abstract view of atoms didn't last, once they began to identify specific physical atoms, such as oxygen. This view fits in with Newton's use of pure (abstract) points such as the 'centre of gravity'.
26. Natural Theory / B. Natural Kinds / 2. Defining Kinds
Natural kinds are defined by their real essence, as in gold having atomic number 79 [Rowlands]
     Full Idea: Part of what it means to be a natural kind is that they are defined by a real essence, a constitution that marks them out as the substance they are (as water is essentially H2O, and gold essentially has atomic number 79).
     From: Mark Rowlands (Externalism [2003], Ch.6)
     A reaction: A 'real essence' would be the opposite of a 'conventional essence', which is just a human way of seeing things.
27. Natural Reality / G. Biology / 4. Ecology
It is common to see the value of nature in one feature, such as life, diversity, or integrity [Rowlands]
     Full Idea: In recent environmental philosophy it is common to see the value of nature identified with one or another natural feature of the environment: life, diversity, ecosystemic integrity and so on.
     From: Mark Rowlands (Externalism [2003], Ch.11)
     A reaction: This thought seems to be asking for the Open Question argument. What is so good about life, or diversity? Our strongest intuition must be that the survival of the ecosystem, and whatever makes that possible, is the highest value.