7 ideas
| 6410 | The only real proper names are 'this' and 'that'; the rest are really definite descriptions. [Russell, by Grayling] |
| Full Idea: Russell argued that the only 'logically proper' names are those which denote particular entities with which one can be acquainted. The best examples are 'this' and 'that'; other apparent names turn out, when analysed, to be definite descriptions. | |
| From: report of Bertrand Russell (On the Nature of Acquaintance [1914]) by A.C. Grayling - Russell Ch.2 | |
| A reaction: This view is firm countered by the causal theory of reference, proposed by Kripke and others, in which not only people like Aristotle are 'baptised' with a name, but also natural kinds such as water. It is hard to disagree with Kripke on this. |
| 3338 | Numbers have been defined in terms of 'successors' to the concept of 'zero' [Peano, by Blackburn] |
| Full Idea: Dedekind and Peano define the number series as the series of successors to the number zero, according to five postulates. | |
| From: report of Giuseppe Peano (works [1890]) by Simon Blackburn - Oxford Dictionary of Philosophy p.279 |
| 5897 | 0 is a non-successor number, all successors are numbers, successors can't duplicate, if P(n) and P(n+1) then P(all-n) [Peano, by Flew] |
| Full Idea: 1) 0 is a number; 2) The successor of any number is a number; 3) No two numbers have the same successor; 4) 0 is not the successor of any number; 5) If P is true of 0, and if P is true of any number n and of its successor, P is true of every number. | |
| From: report of Giuseppe Peano (works [1890]) by Antony Flew - Pan Dictionary of Philosophy 'Peano' | |
| A reaction: Devised by Dedekind and proposed by Peano, these postulates were intended to avoid references to intuition in specifying the natural numbers. I wonder if they could define 'successor' without reference to 'number'. |
| 18439 | Because things can share attributes, we cannot individuate attributes clearly [Quine] |
| Full Idea: No two classes have exactly the same members, but two different attributes may be attributes of exactly the same things. Classes are identical when their members are identical. ...On the other hand, attributes have no clear principle of individuation. | |
| From: Willard Quine (On the Individuation of Attributes [1975], p.100) |
| 18442 | You only know an attribute if you know what things have it [Quine] |
| Full Idea: May we not say that you know an attribute only insofar as you know what things have it? | |
| From: Willard Quine (On the Individuation of Attributes [1975], p.106) | |
| A reaction: Simple, and the best defence of class nominalism (a very implausible theory) which I have encountered. Do I have to know all the things? Do I not know 'red' if I don't know tomatoes have it? |
| 18441 | No entity without identity (which requires a principle of individuation) [Quine] |
| Full Idea: We have an acceptable notion of class, or physical object, or attribute, or any other sort of object, only insofar as we have an acceptable principle of individuation for that sort of object. There is no entity without identity. | |
| From: Willard Quine (On the Individuation of Attributes [1975], p.102) | |
| A reaction: Note that this is his criterion for an 'acceptable' notion. Presumably that is for science. It permits less acceptable notions which don't come up to the standard. And presumably true things can be said about the less acceptable entities. |
| 18440 | Identity of physical objects is just being coextensive [Quine] |
| Full Idea: Physical objects are identical if and only if coextensive. | |
| From: Willard Quine (On the Individuation of Attributes [1975], p.101) | |
| A reaction: The supposed counterexample to this is the statue and the clay it is made of, which are said to have different modal properties (destroying the statue doesn't destroy the clay). |