3 ideas
| 9141 | Abstraction theories build mathematics out of second-order equivalence principles [Cook/Ebert] |
| Full Idea: A theory of abstraction is any account that reconstructs mathematical theories using second-order abstraction principles of the form: §xFx = §xGx iff E(F,G). We ignore first-order abstraction principles such as Frege's direction abstraction. | |
| From: R Cook / P Ebert (Notice of Fine's 'Limits of Abstraction' [2004], 1) | |
| A reaction: Presumably part of the neo-logicist programme, which also uses such principles. The function § (extension operator) 'provides objects corresponding to the argument concepts'. The aim is to build mathematics, rather than the concept of a 'rabbit'. |
| 6005 | Animals are dangerous and nourishing, and can't form contracts of justice [Hermarchus, by Sedley] |
| Full Idea: Hermarchus said that animal killing is justified by considerations of human safety and nourishment and by animals' inability to form contractual relations of justice with us. | |
| From: report of Hermarchus (fragments/reports [c.270 BCE]) by David A. Sedley - Hermarchus | |
| A reaction: Could the last argument be used to justify torturing animals? Or could we eat a human who was too brain-damaged to form contracts? |
| 20716 | False prophets will perform wonders to deceive even the elect [Mark] |
| Full Idea: For false messiahs and false prophets will appear and perform signs and wonders to deceive, if possible, even the elect. | |
| From: St Mark (02: Gospel of St Mark [c.66], 13:22), quoted by Brian Davies - Introduction to the Philosophy of Religion | |
| A reaction: This casts a rather different light on the miracles of Jesus, since they were performed in a context in which even Jesus believed that lots of people (and not just the son of God) could perform miracles. Undermines any Argument from Miracles. |