Combining Texts

All the ideas for 'The Nature of Things', 'The Theory of Knowledge' and 'Reply to Second Objections'

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11 ideas

4. Formal Logic / F. Set Theory ST / 7. Natural Sets
A class is natural when everybody can spot further members of it [Quinton]
     Full Idea: To say that a class is natural is to say that when some of its members are shown to people they pick out others without hesitation and in agreement.
     From: Anthony Quinton (The Nature of Things [1973], 9 'Nat')
     A reaction: He concedes a number of problems with his view, but I admire his attempt to at least begin to distinguish the natural (real!) classes from the ersatz ones. A mention of causal powers would greatly improve his story.
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
Logical constants seem to be entities in propositions, but are actually pure form [Russell]
     Full Idea: 'Logical constants', which might seem to be entities occurring in logical propositions, are really concerned with pure form, and are not actually constituents of the propositions in the verbal expressions of which their names occur.
     From: Bertrand Russell (The Theory of Knowledge [1913], 1.IX)
     A reaction: This seems to entirely deny the existence of logical constants, and yet he says that they are named. Russell was obviously under pressure here from Wittgenstein.
We use logical notions, so they must be objects - but I don't know what they really are [Russell]
     Full Idea: Such words as or, not, all, some, plainly involve logical notions; since we use these intelligently, we must be acquainted with the logical objects involved. But their isolation is difficult, and I do not know what the logical objects really are.
     From: Bertrand Russell (The Theory of Knowledge [1913], 1.IX)
     A reaction: See Idea 23476, from the previous page. Russell is struggling. Wittgenstein was telling him that the constants are rules (shown in truth tables), rather than objects.
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
Logical truths are known by their extreme generality [Russell]
     Full Idea: A touchstone by which logical propositions may be distinguished from all others is that they result from a process of generalisation which has been carried to its utmost limits.
     From: Bertrand Russell (The Theory of Knowledge [1913], p.129), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 7 'What'
7. Existence / D. Theories of Reality / 8. Facts / d. Negative facts
There can't be a negative of a complex, which is negated by its non-existence [Potter on Russell]
     Full Idea: On Russell's pre-war conception it is obvious that a complex cannot be negative. If a complex were true, what would make it false would be its non-existence, not the existence of some other complex.
     From: comment on Bertrand Russell (The Theory of Knowledge [1913]) by Michael Potter - The Rise of Analytic Philosophy 1879-1930 41 'Neg'
     A reaction: It might be false because it doesn't exist, but also 'made' false by a rival complex (such as Desdemona loving Othello).
7. Existence / E. Categories / 5. Category Anti-Realism
Extreme nominalists say all classification is arbitrary convention [Quinton]
     Full Idea: Pure, extreme nominalism sees all classification as the product of arbitrary convention.
     From: Anthony Quinton (The Nature of Things [1973], 9 'Nat')
     A reaction: I'm not sure what the word 'arbitrary' is doing there. Nominalists are not daft, and if they can classify any way they like, they are not likely to choose an 'arbitrary' system. Pragmatism tells the right story here.
8. Modes of Existence / B. Properties / 5. Natural Properties
The naturalness of a class depends as much on the observers as on the objects [Quinton]
     Full Idea: The naturalness of a class depends as essentially on the nature of the observers who classify as it does on the nature of the objects that they classify. ...It depends on our perceptual apparatus, and on our relatively mutable needs and interests.
     From: Anthony Quinton (The Nature of Things [1973], 9 'Nat')
     A reaction: This seems to translate 'natural' as 'natural for us', which is not much use to scientists, who spend quite a lot of effort combating folk wisdom. Do desirable sports cars constitute a natural class?
Properties imply natural classes which can be picked out by everybody [Quinton]
     Full Idea: To say there are properties is to say there are natural classes, classes introduction to some of whose members enables people to pick out others without hesitation and in agreement.
     From: Anthony Quinton (The Nature of Things [1973], 9 'Nat')
     A reaction: Aristotle would like this approach, but it doesn't find many friends among modern logician/philosophers. We should go on to ask why people agree on these things. Causal powers will then come into it.
8. Modes of Existence / D. Universals / 4. Uninstantiated Universals
Uninstantiated properties must be defined using the instantiated ones [Quinton]
     Full Idea: Properties that have no concrete instances must be defined in terms of those that have.
     From: Anthony Quinton (The Nature of Things [1973], 9 'Nat')
     A reaction: I wonder what the dodo used to smell like?
9. Objects / A. Existence of Objects / 5. Individuation / b. Individuation by properties
An individual is a union of a group of qualities and a position [Quinton, by Campbell,K]
     Full Idea: Quinton proposes that an individual is a union of a group of qualities and a position.
     From: report of Anthony Quinton (The Nature of Things [1973], Pt I) by Keith Campbell - The Metaphysic of Abstract Particulars §5
     A reaction: This seems the obvious defence of a bundle account of objects against the charge that indiscernibles would have to be identical. It introduces, however, 'positions' into the ontology, but maybe that price must be paid. Materialism needs space.
11. Knowledge Aims / B. Certain Knowledge / 4. The Cogito
The Cogito is not a syllogism but a self-evident intuition [Descartes]
     Full Idea: When someone says 'I am thinking, therefore I am, or I exist', he does not deduce existence from thought by means of a syllogism, but recognises it as something self-evident by a simple intuition of the mind.
     From: René Descartes (Reply to Second Objections [1641], 140)