| 17208 | A horse would be destroyed if it were changed into a man or an insect [Spinoza] |
| Full Idea: A horse would as much be destroyed if it were changed into a man as if it were changed into an insect. | |
| From: Baruch de Spinoza (The Ethics [1675], IV Pref) | |
| A reaction: He has been referring to essences of things. What if a shire horse is changed into a Shetland pony? If you watched the horse transmute, it would be continuous in a way that two separate creatures are not. Some sort of sameness there. |
| 12904 | If varieties of myself can be conceived of as distinct from me, then they are not me [Leibniz] |
| Full Idea: I can as little conceive of different varieties of myself as of a circle whose diameters are not all of equal length. These variations would all be distinct one from another, and thus one of these varieties of myself would necessarily not be me. | |
| From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.05.13) | |
| A reaction: This seems to be, at the very least, a rejection of any idea that I could have a 'counterpart'. It is unclear, though, where he would place a version of himself who learned a new language, or who might have had, but didn't have, a haircut. |
| 11981 | If someone's life went differently, then that would be another individual [Leibniz] |
| Full Idea: If the life of some person, or something went differently than it does, nothing would stop us from saying that it would be another person, or another possible universe which God had chosen. So truly it would be another individual. | |
| From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.07.14) | |
| A reaction: Plantinga quotes this as an example of 'worldbound individuals'. This sort of remark leads to people saying that Leibniz believes all properties are essential, since they assume that his notion of essence is bound up with identity. But is it? |
| 11027 | To know an object you must know all its possible occurrences [Wittgenstein] |
| Full Idea: If I know an object I also know all its possible occurrences in states of affairs. (Every one of those possibilities must be part of the nature of the object.) A new possibility cannot be discovered later. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.0123) | |
| A reaction: The requirement that you know them 'all' seems absurd, especially if we need science to discover them. I take this idea to be extremely important, and essentially Aristotelian (connecting with the notion of 'potentiality'). We need to know the powers. |
| 23465 | The 'form' of an object is its possible roles in facts [Wittgenstein] |
| Full Idea: The possibility of its occurrence in atomic facts is the form of the object. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.0141) | |
| A reaction: Morris says this picks up the idea from Kant. We might now label the 'form' as the 'modal profile' of the object (a phrase I like). The modern issues over transworld identity seem to be a development of this thought. |
| 12443 | Can an unactualized possible have self-identity, and be distinct from other possibles? [Quine] |
| Full Idea: Is the concept of identity simply inapplicable to unactualized possibles? But what sense can be found in talking of entities which cannot meaningfully be said to be identical with themselve and distinct from one another. | |
| From: Willard Quine (On What There Is [1948], p.4) | |
| A reaction: Can he seriously mean that we are not allowed to talk about possible objects? If I design a house, it is presumably identical to the house I am designing, and distinct from houses I'm not designing. |
| 9203 | We can't quantify in modal contexts, because the modality depends on descriptions, not objects [Quine, by Fine,K] |
| Full Idea: 'Necessarily 9>7' may be true while the sentence 'necessarily the number of planets < 7' is false, even though it is obtained by substituting a coreferential term. So quantification in these contexts is unintelligible, without a clear object. | |
| From: report of Willard Quine (Reference and Modality [1953]) by Kit Fine - Intro to 'Modality and Tense' p. 4 | |
| A reaction: This is Quine's second argument against modality. See Idea 9201 for his first. Fine attempts to refute it. The standard reply seems to be to insist that 9 must therefore be an object, which pushes materialist philosophers into reluctant platonism. |
| 11965 | Could possible Adam gradually transform into Noah, and vice versa? [Chisholm] |
| Full Idea: If Adam lived for 931 years in a possible world, instead of his actual 930 years, ..then Adam and Noah could gradually exchange their ages and other properties...and we could trace Adam in a world back to the actual Noah, and vice versa. | |
| From: Roderick Chisholm (Identity through Possible Worlds [1967], p.81-2) | |
| A reaction: [very compressed] Chisholm was one of the first to raise this problem for possible worlds, though it had been Quine's objection to modal logic all along. Only Adam having essential properties seems to stop this slippery slope, says Chisholm. |
| 14651 | What Socrates could have been, and could have become, are different? [Plantinga] |
| Full Idea: Is there a difference between what Socrates could have been, and what he could have become? | |
| From: Alvin Plantinga (De Re and De Dicto [1969], p.44) | |
| A reaction: That is, I take it, 1) how different might he have been in the past, given how he is now?, and 2) how different might he have been in the past, and now, if he had permanently diverged from how he is now? 1) has tight constraints on it. |
| 16993 | If we discuss what might have happened to Nixon, we stipulate that it is about Nixon [Kripke] |
| Full Idea: There is no reason why we cannot stipulate that, in talking about what would have happened to Nixon in a certain counterfactual situation, we are talking about what would have happened to HIM. | |
| From: Saul A. Kripke (Naming and Necessity lectures [1970], Lecture 1) | |
| A reaction: For many people (including me now, I think) this lays to rest the supposed problem of 'transworld identity' wrestled with by Kaplan and Lewis. |
| 16998 | Transworld identification is unproblematic, because we stipulate that we rigidly refer to something [Kripke] |
| Full Idea: It is because we refer (rigidly) to Nixon, and stipulate that we are speaking of what might have happened to him (under certain circumstances), that 'transworld identifications' are unproblematic in such cases. | |
| From: Saul A. Kripke (Naming and Necessity lectures [1970], Lecture 1) | |
| A reaction: This responds to those who say you need transworld identification before you can rigidly designate something, which has 'reversed the cart and horse' says Kripke. Nice. |
| 17001 | A table in some possible world should not even be identified by its essential properties [Kripke] |
| Full Idea: A table should not be identified with the set or 'bundle' of its properties, nor with the subset of its essential properties. Don't ask: how can I identify this table in another possible world, except by its properties? I have the table in my hands. | |
| From: Saul A. Kripke (Naming and Necessity lectures [1970], Lecture 1) | |
| A reaction: You identify the table by what's in front of you, but the essence might be relevant to deciding how far this table could change and remain this table. |
| 4952 | Identification across possible worlds does not need properties, even essential ones [Kripke] |
| Full Idea: Some properties of an object may be essential to it, in that it could not have failed to have them. But these properties are not used to identify the object in another possible world, for such an identification is not needed. | |
| From: Saul A. Kripke (Naming and Necessity lectures [1970], Lecture 1) | |
| A reaction: So how DO you identify objects in other possible worlds, or in this one? You may say he was baptised 'Aristotle' so that's rigid, but if Athens is full of pseudo-Aristotles I want to pick out the real one. I say Kripke muddles epistemology and ontology. |
| 11982 | If possible Socrates differs from actual Socrates, the Indiscernibility of Identicals says they are different [Plantinga] |
| Full Idea: If the Socrates of the actual world has snubnosedness but Socrates-in-W does not, this is surely inconsistent with the Indiscernibility of Identicals, a principle than which none sounder can be conceived. | |
| From: Alvin Plantinga (Transworld Identity or worldbound Individuals? [1973], I) | |
| A reaction: However, we allow Socrates to differ over time while remaining the same Socrates, so some similar approach should apply here. In both cases we need some notion of what is essential to Socrates. But what unites aged 3 with aged 70? |
| 11983 | It doesn't matter that we can't identify the possible Socrates; we can't identify adults from baby photos [Plantinga] |
| Full Idea: We may say it makes no sense to say that Socrates exists at a world, if there is in principle no way of identifying him. ...But this is confused. To suppose Agnew was a precocious baby, we needn't be able to pick him from a gallery of babies. | |
| From: Alvin Plantinga (Transworld Identity or worldbound Individuals? [1973], I) | |
| A reaction: This seems a good point, and yet we have a space-time line joining adult Agnew with baby Agnew, and no such causal link is available between persons in different possible worlds. What would be the criterion in each case? |
| 11985 | If individuals can only exist in one world, then they can never lack any of their properties [Plantinga] |
| Full Idea: The Theory of Worldbound Individuals contends that no object exists in more than one possible world; this implies the outrageous view that - taking properties in the broadest sense - no object could have lacked any property that it in fact has. | |
| From: Alvin Plantinga (Transworld Identity or worldbound Individuals? [1973], II) | |
| A reaction: Leibniz is the best known exponent of this 'outrageous view', though Plantinga shows that Lewis may be seen in the same light, since only counterparts are found in possible worlds, not the real thing. The Theory does seem wrong. |
| 11971 | The simplest solution to transworld identification is to adopt bare particulars [Kaplan] |
| Full Idea: If we adopt the bare particular metaphysical view, we have a simple solution to the transworld identification problem: we identify by bare particulars. | |
| From: David Kaplan (Transworld Heir Lines [1967], p.98) | |
| A reaction: See Ideas 11969 and 11970 on this idea. The problem with bare particulars is that they can change their properties utterly, so that Aristotle in the actual world can be a poached egg in some possible world. We need essences. |
| 12765 | Why imagine that Babe Ruth might be a billiard ball; nothing useful could be said about the ball [Stalnaker] |
| Full Idea: I cannot think of any point in making the counterfactual supposition that Babe Ruth is a billiard ball; there is nothing I can say about him in that imagined state that I could not just as well say about billiard balls that are not him. | |
| From: Robert C. Stalnaker (Anti-essentialism [1979], p.79) | |
| A reaction: A bizarrely circumspect semanticists way of saying that Ruth couldn't possibly be a billiard ball! Would he say the same about a group of old men in wheelchairs, one of whom IS Babe Ruth? |
| 14072 | Possible worlds identity needs a sortal [Gibbard] |
| Full Idea: Identity across possible worlds makes sense only with respect to a sortal | |
| From: Allan Gibbard (Contingent Identity [1975], IV) | |
| A reaction: See Gibbard's other ideas from this paper. I fear that the sortal invoked is too uncertain and slippery to do any useful job, and I can't see any principled difficulty with naming something before you can think of a sortal for it. |
| 14078 | Only concepts, not individuals, can be the same across possible worlds [Gibbard] |
| Full Idea: It is meaningless to talk of the same concrete thing in different possible worlds, ...but it makes sense to speak of the same individual concept, which is just a function which assigns to each possible world in a set an individual in that world. | |
| From: Allan Gibbard (Contingent Identity [1975], VII) | |
| A reaction: A lovely bold response to the problem of transworld identity, but one which needs investigation. It sounds very promising to me. 'Aristotle' is a cocept, not a name. There is no separate category of 'names'. Wow. (Attach dispositions to concepts?). |
| 12011 | Transworld identity concerns the limits of possibility for ordinary things [Forbes,G] |
| Full Idea: An elucidation of transworld identity can be regarded as an elucidation of the boundaries of possibility for ordinary things. | |
| From: Graeme Forbes (The Metaphysics of Modality [1985], 5.1) | |
| A reaction: I presume that if we don't search for some such criterion, we just have to face the possibility that Aristotle could have been a poached egg in some possible world. To know the bounds of possibility, study the powers of actual objects. |
| 12016 | The problem of transworld identity can be solved by individual essences [Forbes,G] |
| Full Idea: The motivation for investigating individual essences should be obvious, since if every object has such an essence, the problem of elucidating transworld identity can be solved. | |
| From: Graeme Forbes (The Metaphysics of Modality [1985], 5.1) | |
| A reaction: It is important that, if necessary, the identities be 'individual', and not just generic, by sortal, or natural kind. We want to reason about (and explain) truths at the fine-grained level of the individual, not just at the broad level of generalisation. |
| 13725 | □ must be sensitive as to whether it picks out an object by essential or by contingent properties [Fitting/Mendelsohn] |
| Full Idea: If □ is to be sensitive to the quality of the truth of a proposition in its scope, then it must be sensitive as to whether an object is picked out by an essential property or by a contingent one. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 4.3) | |
| A reaction: This incredibly simple idea strikes me as being powerful and important. ...However, creating illustrative examples leaves me in a state of confusion. You try it. They cite '9' and 'number of planets'. But is it just nominal essence? '9' must be 9. |
| 13731 | Objects retain their possible properties across worlds, so a bundle theory of them seems best [Fitting/Mendelsohn] |
| Full Idea: The property of 'possibly being a Republican' is as much a property of Bill Clinton as is 'being a democrat'. So we don't peel off his properties from world to world. Hence the bundle theory fits our treatment of objects better than bare particulars. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 7.3) | |
| A reaction: This bundle theory is better described in recent parlance as the 'modal profile'. I am reluctant to talk of a modal truth about something as one of its 'properties'. An objects, then, is a bundle of truths? |
| 15377 | Definite descriptions pick out different objects in different possible worlds [Fitting] |
| Full Idea: Definite descriptions pick out different objects in different possible worlds quite naturally. | |
| From: Melvin Fitting (Intensional Logic [2007], 3.4) | |
| A reaction: A definite description can pick out the same object in another possible world, or a very similar one, or an object which has almost nothing in common with the others. |
| 13081 | Even extreme modal realists might allow transworld identity for abstract objects [Cover/O'Leary-Hawthorne] |
| Full Idea: It might be suggested that even the extreme modal realist can countenance transworld identity for abstract objects. | |
| From: Cover,J/O'Leary-Hawthorne,J (Substance and Individuation in Leibniz [1999], 3.2.2 n46) | |
| A reaction: This may sound right for uncontroversial or well-defined abstracta such as numbers and circles, but even 'or' is ambiguous, and heaven knows what the transworld identity of 'democracy' is! |
| 12235 | Necessity of identity seems trivial, because it leaves out the real essence [Oderberg] |
| Full Idea: The necessity of identity carries the appearance of triviality, because it is the eviscerated contemporary essentialist form of a foundational real essentialist truth to the effect that every object has its own nature. | |
| From: David S. Oderberg (Real Essentialism [2007], 1.1) | |
| A reaction: I like this. Writers like Mackie and Forbes have to put the 'trivial' aspects of essence to one side, without ever seeing why there is such a problem. Real substantial essences have necessity of identity as a side-effect. |
| 13717 | Transworld identity is not a problem in de dicto sentences, which needn't identify an individual [Sider] |
| Full Idea: There is no problem of transworld identification with de dicto modal sentence, for their evaluation does not require taking an individual from one possible world and reidentifying it in another. | |
| From: Theodore Sider (Logic for Philosophy [2010], 9.2) | |
| A reaction: If 'de dicto' is about the sentence and 'de re' is about the object (Idea 5732), how do you evaluate the sentence without at least some notion of the object to which it refers. Nec the Prime Minister chairs the cabinet. Could a poached egg do the job? |
| 15176 | The individuals and kinds involved in modality are also a matter of convention [Sidelle] |
| Full Idea: It is not merely the modal facts that result from our conventions, but the individuals and kinds that are modally involved. | |
| From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.3) | |
| A reaction: I am beginning to find Sidelle's views very sympathetic - going over to the Dark Side, I'm afraid. But conventions won't work at all if they don't correspond closely to reality. |
| 12889 | The limits of change for an individual depend on the kind of individual [Simons] |
| Full Idea: What determines the limits of admissible change and secures the identity of a continuant is a matter of the kind of object in question. | |
| From: Peter Simons (Parts [1987], 9.6) | |
| A reaction: This gives some motivation for the sortal view of essence, which I find hard to take. However, if my statue were pulverised it would make good compost. |
| 11887 | Transworld identity without individual essences leads to 'bare identities' [Mackie,P] |
| Full Idea: Transworld identity without individual essences leads to 'bare identities'. | |
| From: Penelope Mackie (How Things Might Have Been [2006], 2.7) | |
| A reaction: [She gives an argument for this, based on Forbes] I certainly favour the notion of individual essences over the notion of bare identities. We must distinguish identity in reality from identity in concept. Identities are points in conceptual space. |