22 ideas
16974 | The nature of each logical concept is given by a collection of inference rules [Correia] |
Full Idea: The view presented here presupposes that each logical concept is associated with some fixed and well defined collection of rules of inference which characterize its basic logical nature. | |
From: Fabrice Correia (On the Reduction of Necessity to Essence [2012], 4) | |
A reaction: [He gives Fine's 'Senses of Essences' 57-8 as a source] He seems to have in mind natural deduction, where the rules are for the introduction and elimination of the concepts. |
9148 | I think of variables as objects rather than as signs [Fine,K] |
Full Idea: It is natural nowadays to think of variables as a certain kind of sign, but I wish to think of them as a certain kind of object. | |
From: Kit Fine (Cantorian Abstraction: Recon. and Defence [1998], §2) | |
A reaction: Fine has a theory based on 'arbitrary objects', which is a rather charming idea. The cell of a spreadsheet is a kind of object, I suppose. A variable might be analogous to a point in space, where objects can locate themselves. |
17518 | Counting 'coin in this box' may have coin as the unit, with 'in this box' merely as the scope [Ayers] |
Full Idea: If we count the concept 'coin in this box', we could regard coin as the 'unit', while taking 'in this box' to limit the scope. Counting coins in two boxes would be not a difference in unit (kind of object), but in scope. | |
From: M.R. Ayers (Individuals without Sortals [1974], 'Counting') | |
A reaction: This is a very nice alternative to the Fregean view of counting, depending totally on the concept, and rests more on a natural concept of object. I prefer Ayers. Compare 'count coins till I tell you to stop'. |
17516 | If counting needs a sortal, what of things which fall under two sortals? [Ayers] |
Full Idea: If we accepted that counting objects always presupposes some sortal, it is surely clear that the class of objects to be counted could be designated by two sortals rather than one. | |
From: M.R. Ayers (Individuals without Sortals [1974], 'Realist' vii) | |
A reaction: His nice example is an object which is both 'a single piece of wool' and a 'sweater', which had better not be counted twice. Wiggins struggles to argue that there is always one 'substance sortal' which predominates. |
17520 | Events do not have natural boundaries, and we have to set them [Ayers] |
Full Idea: In order to know which event has been ostensively identified by a speaker, the auditor must know the limits intended by the speaker. ...Events do not have natural boundaries. | |
From: M.R. Ayers (Individuals without Sortals [1974], 'Concl') | |
A reaction: He distinguishes events thus from natural objects, where the world, to a large extent, offers us the boundaries. Nice point. |
17519 | To express borderline cases of objects, you need the concept of an 'object' [Ayers] |
Full Idea: The only explanation of the power to produce borderline examples like 'Is this hazelnut one object or two?' is the possession of the concept of an object. | |
From: M.R. Ayers (Individuals without Sortals [1974], 'Counting') |
17510 | Speakers need the very general category of a thing, if they are to think about it [Ayers] |
Full Idea: If a speaker indicates something, then in order for others to catch his reference they must know, at some level of generality, what kind of thing is indicated. They must categorise it as event, object, or quality. Thinking about something needs that much. | |
From: M.R. Ayers (Individuals without Sortals [1974], Intro) | |
A reaction: Ayers defends the view that such general categories are required, but not the much narrower sortal terms defended by Geach and Wiggins. I'm with Ayers all the way. 'What the hell is that?' |
17522 | We use sortals to classify physical objects by the nature and origin of their unity [Ayers] |
Full Idea: Sortals are the terms by which we intend to classify physical objects according to the nature and origin of their unity. | |
From: M.R. Ayers (Individuals without Sortals [1974], 'Concl') | |
A reaction: This is as opposed to using sortals for the initial individuation. I take the perception of the unity to come first, so resemblance must be mentioned, though it can be an underlying (essentialist) resemblance. |
17515 | Seeing caterpillar and moth as the same needs continuity, not identity of sortal concepts [Ayers] |
Full Idea: It is unnecessary to call moths 'caterpillars' or caterpillars 'moths' to see that they can be the same individual. It may be that our sortal concepts reflect our beliefs about continuity, but our beliefs about continuity need not reflect our sortals. | |
From: M.R. Ayers (Individuals without Sortals [1974], 'Realist' vi) | |
A reaction: Something that metamorphosed through 15 different stages could hardly required 15 different sortals before we recognised the fact. Ayers is right. |
17511 | Recognising continuity is separate from sortals, and must precede their use [Ayers] |
Full Idea: The recognition of the fact of continuity is logically independent of the possession of sortal concepts, whereas the formation of sortal concepts is at least psychologically dependent upon the recognition of continuity. | |
From: M.R. Ayers (Individuals without Sortals [1974], Intro) | |
A reaction: I take this to be entirely correct. I might add that unity must also be recognised. |
17517 | Could the same matter have more than one form or principle of unity? [Ayers] |
Full Idea: The abstract question arises of whether the same matter could be subject to more than one principle of unity simultaneously, or unified by more than one 'form'. | |
From: M.R. Ayers (Individuals without Sortals [1974], 'Realist' vii) | |
A reaction: He suggests that the unity of the sweater is destroyed by unravelling, and the unity of the thread by cutting. |
17513 | If there are two objects, then 'that marble, man-shaped object' is ambiguous [Ayers] |
Full Idea: The statue is marble and man-shaped, but so is the piece of marble. So not only are the two objects in the same place, but two marble and man-shaped objects in the same place, so 'that marble, man-shaped object' must be ambiguous or indefinite. | |
From: M.R. Ayers (Individuals without Sortals [1974], 'Prob') | |
A reaction: It strikes me as basic that it can't be a piece of marble if you subtract its shape, and it can't be a statue if you subtract its matter. To treat a statue as an object, separately from its matter, is absurd. |
17523 | Sortals basically apply to individuals [Ayers] |
Full Idea: Sortals, in their primitive use, apply to the individual. | |
From: M.R. Ayers (Individuals without Sortals [1974], 'Concl') | |
A reaction: If the sortal applies to the individual, any essence must pertain to that individual, and not to the class it has been placed in. |
17521 | You can't have the concept of a 'stage' if you lack the concept of an object [Ayers] |
Full Idea: It would be impossible for anyone to have the concept of a stage who did not already possess the concept of a physical object. | |
From: M.R. Ayers (Individuals without Sortals [1974], 'Concl') |
17514 | Temporal 'parts' cannot be separated or rearranged [Ayers] |
Full Idea: Temporally extended 'parts' are still mysteriously inseparable and not subject to rearrangement: a thing cannot be cut temporally in half. | |
From: M.R. Ayers (Individuals without Sortals [1974], 'Prob') | |
A reaction: A nice warning to anyone accepting a glib analogy between spatial parts and temporal parts. |
17509 | Some say a 'covering concept' completes identity; others place the concept in the reference [Ayers] |
Full Idea: Some hold that the 'covering concept' completes the incomplete concept of identity, determining the kind of sameness involved. Others strongly deny the identity itself is incomplete, and locate the covering concept within the necessary act of reference. | |
From: M.R. Ayers (Individuals without Sortals [1974], Intro) | |
A reaction: [a bit compressed; Geach is the first view, and Quine the second; Wiggins is somewhere between the two] |
17512 | If diachronic identities need covering concepts, why not synchronic identities too? [Ayers] |
Full Idea: Why are covering concepts required for diachronic identities, when they must be supposed unnecessary for synchronic identities? | |
From: M.R. Ayers (Individuals without Sortals [1974], 'Prob') |
16973 | Explain logical necessity by logical consequence, or the other way around? [Correia] |
Full Idea: One view is that logical consequence is to be understood in terms of logical necessity (some proposition holds necessarily, if some group of other propositions holds). Alternatively, logical necessity is a logical consequence of the empty set. | |
From: Fabrice Correia (On the Reduction of Necessity to Essence [2012], 3) | |
A reaction: I think my Finean preference is for all necessities to have a 'necessitator', so logical necessity results from logic in some way, perhaps from logical consequence, or from the essences of the connectives and operators. |
9152 | If green is abstracted from a thing, it is only seen as a type if it is common to many things [Fine,K] |
Full Idea: In traditional abstraction, the colour green merely has the intrinsic property of being green, other properties of things being abstracted away. But why should that be regarded as a type? It must be because the property is common to the instances. | |
From: Kit Fine (Cantorian Abstraction: Recon. and Defence [1998], §5) | |
A reaction: A nice question which shows that the much-derided single act of abstraction is not sufficient to arrive at a concept, so that abstraction is a more complex matter (perhaps even a rational one) than simple empiricists believe. |
9149 | To obtain the number 2 by abstraction, we only want to abstract the distinctness of a pair of objects [Fine,K] |
Full Idea: In abstracting from the elements of a doubleton to obtain 2, we do not wish to abstract away from all features of the objects. We wish to take account of the fact that the two objects are distinct; this alone should be preserved under abstraction. | |
From: Kit Fine (Cantorian Abstraction: Recon. and Defence [1998], §3) | |
A reaction: This is Fine's strategy for meeting Frege's objection to abstraction, summarised in Idea 9146. It seems to use the common sense idea that abstraction is not all-or-nothing. Abstraction has degrees (and levels). |
9150 | We should define abstraction in general, with number abstraction taken as a special case [Fine,K] |
Full Idea: Number abstraction can be taken to be a special case of abstraction in general, which can then be defined without recourse to the concept of number. | |
From: Kit Fine (Cantorian Abstraction: Recon. and Defence [1998], §3) | |
A reaction: At last, a mathematical logician recognising that they don't have a monopoly on abstraction. It is perfectly obvious that abstractions of simple daily concepts must be chronologically and logically prior to number abstraction. Number of what? |
9146 | After abstraction all numbers seem identical, so only 0 and 1 will exist! [Fine,K] |
Full Idea: In Cantor's abstractionist account there can only be two numbers, 0 and 1. For abs(Socrates) = abs(Plato), since their numbers are the same. So the number of {Socrates,Plato} is {abs(Soc),abs(Plato)}, which is the same number as {Socrates}! | |
From: Kit Fine (Cantorian Abstraction: Recon. and Defence [1998], §1) | |
A reaction: Fine tries to answer this objection, which arises from §45 of Frege's Grundlagen. Fine summarises that "indistinguishability without identity appears to be impossible". Maybe we should drop talk of numbers in terms of sets. |