more on this theme | more from this thinker
Full Idea
Frege fixed on construing real numbers as ratios of quantities (in agreement with Newton).
Gist of Idea
Real numbers are ratios of quantities
Source
report of Gottlob Frege (Grundgesetze der Arithmetik 2 (Basic Laws) [1903]) by Michael Dummett - Frege philosophy of mathematics Ch.20
Book Ref
Dummett,Michael: 'Frege: philosophy of mathematics' [Duckworth 1991], p.261
A Reaction
If 3/4 is the same real number as 6/8, which is the correct ratio? Why doesn't the square root of 9/16 also express it? Why should irrationals be so utterly different from rationals? In what sense are they both 'numbers'?
| 13886 | Later Frege held that definitions must fix a function's value for every possible argument [Frege, by Wright,C] |
| 9889 | Real numbers are ratios of quantities [Frege, by Dummett] |
| 10553 | A number is a class of classes of the same cardinality [Frege, by Dummett] |
| 10020 | Frege's biggest error is in not accounting for the senses of number terms [Hodes on Frege] |
| 9886 | Cardinals say how many, and reals give measurements compared to a unit quantity [Frege] |
| 9890 | The modern account of real numbers detaches a ratio from its geometrical origins [Frege] |
| 9891 | The first demand of logic is of a sharp boundary [Frege] |
| 10019 | Only what is logically complex can be defined; what is simple must be pointed to [Frege] |
| 9845 | We can't define a word by defining an expression containing it, as the remaining parts are a problem [Frege] |
| 9887 | Formalism misunderstands applications, metatheory, and infinity [Frege, by Dummett] |
| 8751 | Only applicability raises arithmetic from a game to a science [Frege] |
| 11846 | If we abstract the difference between two houses, they don't become the same house [Frege] |