Combining Philosophers

All the ideas for Derek Parfit, Henry of Ghent and Alan Musgrave

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25 ideas

2. Reason / E. Argument / 7. Thought Experiments
Imaginary cases are good for revealing our beliefs, rather than the truth [Parfit]
     Full Idea: I believe it is worth considering imaginary cases (such as Teletransportation), as we can use them to discover, not what the truth is, but what we believe.
     From: Derek Parfit (The Unimportance of Identity [1995], p.293)
     A reaction: The trouble is that we might say that IF I were suddenly turned into a pig, then I would come to believe in dualism, but that will not and cannot happen, because dualism is false. It seems essential to accept the natural possibility of the case.
5. Theory of Logic / C. Ontology of Logic / 3. If-Thenism
The If-thenist view only seems to work for the axiomatised portions of mathematics [Musgrave]
     Full Idea: The If-thenist view seems to apply straightforwardly only to the axiomatised portions of mathematics.
     From: Alan Musgrave (Logicism Revisited [1977], §5)
     A reaction: He cites Lakatos to show that cutting-edge mathematics is never axiomatised. One might reply that if the new mathematics is any good then it ought to be axiomatis-able (barring Gödelian problems).
Perhaps If-thenism survives in mathematics if we stick to first-order logic [Musgrave]
     Full Idea: If we identify logic with first-order logic, and mathematics with the collection of first-order theories, then maybe we can continue to maintain the If-thenist position.
     From: Alan Musgrave (Logicism Revisited [1977], §5)
     A reaction: The problem is that If-thenism must rely on rules of inference. That seems to mean that what is needed is Soundness, rather than Completeness. That is, inference by the rules must work properly.
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
Logical truths may contain non-logical notions, as in 'all men are men' [Musgrave]
     Full Idea: Containing only logical notions is not a necessary condition for being a logical truth, since a logical truth such as 'all men are men' may contain non-logical notions such as 'men'.
     From: Alan Musgrave (Logicism Revisited [1977], §3)
     A reaction: [He attributes this point to Russell] Maybe it is only a logical truth in its general form, as ∀x(x=x). Of course not all 'banks' are banks.
A statement is logically true if it comes out true in all interpretations in all (non-empty) domains [Musgrave]
     Full Idea: The standard modern view of logical truth is that a statement is logically true if it comes out true in all interpretations in all (non-empty) domains.
     From: Alan Musgrave (Logicism Revisited [1977], §3)
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / d. Peano arithmetic
No two numbers having the same successor relies on the Axiom of Infinity [Musgrave]
     Full Idea: The axiom of Peano which states that no two numbers have the same successor requires the Axiom of Infinity for its proof.
     From: Alan Musgrave (Logicism Revisited [1977], §4 n)
     A reaction: [He refers to Russell 1919:131-2] The Axiom of Infinity is controversial and non-logical.
6. Mathematics / C. Sources of Mathematics / 7. Formalism
Formalism seems to exclude all creative, growing mathematics [Musgrave]
     Full Idea: Formalism seems to exclude from consideration all creative, growing mathematics.
     From: Alan Musgrave (Logicism Revisited [1977], §5)
     A reaction: [He cites Lakatos in support] I am not immediately clear why spotting the remote implications of a formal system should be uncreative. The greatest chess players are considered to be highly creative and imaginative.
Formalism is a bulwark of logical positivism [Musgrave]
     Full Idea: Formalism is a bulwark of logical positivist philosophy.
     From: Alan Musgrave (Logicism Revisited [1977], §5)
     A reaction: Presumably if you drain all the empirical content out of arithmetic and geometry, you are only left with the bare formal syntax, of symbols and rules. That seems to be as analytic as you can get.
7. Existence / C. Structure of Existence / 2. Reduction
Reduction can be by identity, or constitution, or elimination [Parfit, by PG]
     Full Idea: We can distinguish Identifying Reductionism (as in 'persons are bodies'), or Constitutive Reductionism (as in 'persons are distinct, but consist of thoughts etc.'), or Eliminative Reductionism (as in 'there are no persons, only thoughts etc.').
     From: report of Derek Parfit (The Unimportance of Identity [1995], p.295) by PG - Db (ideas)
     A reaction: Constitutive Reductionism seems the most common one, as in 'chemistry just consists of lots of complicated physics'. He doesn't mention bridge laws, which are presumably only required in more complicated cases of constitutive reduction.
7. Existence / E. Categories / 3. Proposed Categories
Substance, Quantity and Quality are real; other categories depend on those three [Henry of Ghent]
     Full Idea: Among creatures there are only three 'res' belong to the three first categories: Substance, Quantity and Quality. All other are aspects [rationes] and intellectual concepts with respect to them, with reality only as grounded on the res of those three.
     From: Henry of Ghent (Quodlibeta [1284], VII:1-2), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 12.3
     A reaction: Pasnau connects with the 'arrangement of being', giving an 'ontologically innocent' structure to reality. That seems to be what we all want, if only we could work out the ontologically guilty bit.
8. Modes of Existence / A. Relations / 1. Nature of Relations
The only reality in the category of Relation is things from another category [Henry of Ghent]
     Full Idea: There is beyond a doubt nothing real in the category of Relation, except what is a thing from another category.
     From: Henry of Ghent (Quodlibeta [1284], VII:1-2), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 12.3
     A reaction: This seems to have been the fairly orthodox scholastic view of relations.
8. Modes of Existence / B. Properties / 8. Properties as Modes
Accidents are diminished beings, because they are dispositions of substance (unqualified being) [Henry of Ghent]
     Full Idea: Accidents are beings only in a qualified and diminished sense, because they are not called beings, nor are they beings, except because they are dispositions of an unqualified being, a substance.
     From: Henry of Ghent (Quodlibeta [1284], XV.5), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 10.4
     A reaction: This is aimed to 'half' detach the accidents (as the Eucharist requires). Later scholastics detached them completely. Late scholastics seem to have drifted back to Henry's view. The equivocal use of 'being' here was challenged later.
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / b. Transcendental idealism
Kant says things-in-themselves cause sensations, but then makes causation transcendental! [Henry of Ghent, by Pinkard]
     Full Idea: Kant claimed that things-in-themselves caused our sensations; but causality was a transcendental condition of experience, not a property of things-in-themselves, so the great Kant had contradicted himself.
     From: report of Henry of Ghent (Quodlibeta [1284], Supplement) by Terry Pinkard - German Philosophy 1760-1860 04
     A reaction: This early objection by the conservative Jacobi (who disliked Enlightenment rational religion) is the key to the dispute over whether Kant is an idealist. Kant denied being an idealist, but how can he be, if this idea is correct?
16. Persons / B. Nature of the Self / 5. Self as Associations
Personal identity is just causally related mental states [Parfit, by Maslin]
     Full Idea: For Parfit all personal identity really amounts to is a chain of experiences and other psychological features causally related to each other in 'direct' sorts of ways.
     From: report of Derek Parfit (Personal Identity [1971]) by Keith T. Maslin - Introduction to the Philosophy of Mind 10.5
     A reaction: When summarised like this, it strikes me that Parfit is just false to our experience, whatever Hume may say. I suspect that Parfit (and those like him) concentrate too much on rather passive perceptual experience, and neglect the will.
16. Persons / D. Continuity of the Self / 1. Identity and the Self
Psychologists are interested in identity as a type of person, but philosophers study numerical identity [Parfit]
     Full Idea: When psychologists discuss identity, they are typically concerned with the kind of person someone is, or wants to be (as in an 'identity crisis'). But when philosophers discuss identity, it is numerical identity they mean.
     From: Derek Parfit (The Unimportance of Identity [1995], p.293)
     A reaction: I think it is important to note that the philosophical problem breaks down into two areas: whether I have numerical identity with myself over time, and whether other people have it. It may be that two different sets of criteria will emerge.
16. Persons / D. Continuity of the Self / 2. Mental Continuity / b. Self as mental continuity
One of my future selves will not necessarily be me [Parfit]
     Full Idea: If I say 'It will not be me, but one of my future selves', I do not imply that I will be that future self. He is one of my later selves, and I am one of his earlier selves. There is no underlying person we both are.
     From: Derek Parfit (Personal Identity [1971], §5)
     A reaction: The problem here seems to be explaining why I should care about my later self, if it isn't me. If the answer is only that it will be psychologically very similar to me, then I would care more about my current identical twin than about my future self.
If my brain-halves are transplanted into two bodies, I have continuity, and don't need identity [Parfit]
     Full Idea: If the two halves of my brain are transplanted into different bodies just like mine, they cannot both be me, since that would make them the same person. ..But my relation to these two contains everything that matters, so identity is not what matters.
     From: Derek Parfit (The Unimportance of Identity [1995], p.314)
     A reaction: I challenge his concept of what 'matters'. He has a rather solipsistic view of the problem, and I take Parfit to be a rather unsociable person, since his friends and partner will be keenly interested in the identities of the new beings.
Over a period of time what matters is not that 'I' persist, but that I have psychological continuity [Parfit]
     Full Idea: We should revise our view about identity over time: what matters isn't that there will be someone alive who will be me; it is rather that there should be at least one living person who will be psychologically continuous with me as I am now.
     From: Derek Parfit (The Unimportance of Identity [1995], p.316)
     A reaction: Parfit and Locke seem to agree on this, and it is no accident that they both like 'science fiction' examples. Apparently Parfit wouldn't bat an eyelid if someone threatened to cut his corpus callosum. I rate it as a catastrophe for my current existence.
16. Persons / D. Continuity of the Self / 4. Split Consciousness
If we split like amoeba, we would be two people, neither of them being us [Parfit]
     Full Idea: In the case of the man who, like an amoeba, divides….we can suggest that he survives as two different people without implying that he is those people.
     From: Derek Parfit (Personal Identity [1971], §1)
     A reaction: Maybe an amoeba is a homogeneous substance for which splitting is insignificant, but when a person has certain parts that are totally crucial, splitting them is catastrophic, and quite different. I'm not sure that splitting a self would leave persons.
It is fine to save two dying twins by merging parts of their bodies into one, and identity is irrelevant [Parfit]
     Full Idea: If I am largely paralysed, and my twin brother is dying of brain disease, then if the operation to graft my head onto his body is offered, I should accept the operation, and it is irrelevant whether this person would be me.
     From: Derek Parfit (The Unimportance of Identity [1995], p.308)
     A reaction: Parfit notes that the brain is a particularly significant part of the process. The fact that I might cheerfully accept this offer without philosophical worries doesn't get rid of the question 'who is this person?' Who should they remain married to?
If two humans are merged surgically, the new identity is a purely verbal problem [Parfit]
     Full Idea: If there is someone with my head and my brother's body, it is a merely verbal question whether that person will be me, and that is why, even if it won't be me, that doesn't matter. ..What matters is not identity, but the facts of which identity consists.
     From: Derek Parfit (The Unimportance of Identity [1995], p.310)
     A reaction: It strikes me that from the subjective psychological point of view identity is of little interest, but from the objective external viewpoint (e.g. the forensic one) such questions are highly significant, and rightly so.
16. Persons / D. Continuity of the Self / 5. Concerns of the Self
Concern for our own lives isn't the source of belief in identity, it is the result of it [Parfit]
     Full Idea: Egoism, and the fear not of near but of distant death, and the regret that so much of one's life should have gone by - these are not, I think, wholly natural or instinctive. They are strengthened by a false belief in stable identity.
     From: Derek Parfit (Personal Identity [1971], §6)
     A reaction: This raises some very nice questions, about the extent to which various aspects of self-concern are instinctive and natural, or culturally induced, and even totally misguided and false. I can worry about the distant death of my guinea pig, or my grandson.
16. Persons / E. Rejecting the Self / 4. Denial of the Self
It doesn't matter whether I exist with half my components replaced (any more than an audio system) [Parfit]
     Full Idea: It is quite uninteresting whether, with half its components replaced, I have the same audio system, and also whether I exist if half of my body were simultaneously replaced.
     From: Derek Parfit (The Unimportance of Identity [1995], p.302)
     A reaction: It is impossible to deny this, if the part replaced is not the brain. My doubt about Parfit's thesis is that while I may not care whether some modified thing is still me, my lawyers and the police might be very concerned.
19. Language / A. Nature of Meaning / 5. Meaning as Verification
Logical positivists adopted an If-thenist version of logicism about numbers [Musgrave]
     Full Idea: Logical positivists did not adopt old-style logicism, but rather logicism spiced with varying doses of If-thenism.
     From: Alan Musgrave (Logicism Revisited [1977], §4)
     A reaction: This refers to their account of mathematics as a set of purely logical truths, rather than being either empirical, or a priori synthetic.
23. Ethics / E. Utilitarianism / 1. Utilitarianism
We should focus less on subjects of experience, and more on the experiences themselves [Parfit]
     Full Idea: It becomes more plausible, when thinking morally, to focus less upon the person, the subject of experiences, and instead to focus more upon the experiences themselves.
     From: Derek Parfit (Reasons and Persons [1984], §116)
     A reaction: This pinpoints how Parfit moves from a view of persons in terms of continuity of consciousness to a utilitarian morality. It brings out nicely what is wrong with utilitarianism - the reductio of a great ball of nice experiences, with no one having them.