3 ideas
| 21548 | The null class is the class with all the non-existents as its members [MacColl, by Lackey] |
| Full Idea: In 1905 the Scottish logician Hugh MacColl published a paper in which he argued that the null class in logic should be taken as the class with all the non-existents as its members. | |
| From: report of Hugh MacColl (Symbolic Reasoning [1905]) by Douglas Lackey - Intros to Russell's 'Essays in Analysis' p.95 | |
| A reaction: For the null object (zero) Frege just chose one sample concept with an empty extension. MacColl's set seems to have a lot of members, given that it is 'null'. How many, I wonder? Russell responded to this paper. |
| 8638 | Thomae's idea of abstract from peculiarities gives a general concept, and leaves the peculiarities [Frege on Thomae] |
| Full Idea: When Thomae says "abstract from the peculiarities of the individual members of a set of items", or "disregard those characteristics which serve to distinguish them", we get a general concept under which they fall. The things keep their characteristics. | |
| From: comment on C.J. Thomae (works [1869], §34) by Gottlob Frege - Grundlagen der Arithmetik (Foundations) §34 | |
| A reaction: Interesting. You don't have to leave out their distinctive fur in order to count cats. But you have to focus on some aspect of them, because they aren't 'three meats'. |
| 1513 | The Egyptians were the first to say the soul is immortal and reincarnated [Herodotus] |
| Full Idea: The Egyptians were the first to claim that the soul of a human being is immortal, and that each time the body dies the soul enters another creature just as it is being born. | |
| From: Herodotus (The Histories [c.435 BCE], 2.123.2) |