3 ideas
| 17750 | The first clear proof of the consistency of the first order predicate logic was in 1928 [Hilbert/Ackermann, by Walicki] |
| Full Idea: The first clear proof of the consistency of the first order predicate logic is found in the 1928 book of Hilbert and Ackermann. | |
| From: report of Hilbert,D/Ackermann,W (Principles of Theoretical Logic [1928]) by Michal Walicki - Introduction to Mathematical Logic History E.2.1 |
| 15034 | Are genera and species real or conceptual? bodies or incorporeal? in sensibles or separate from them? [Porphyry] |
| Full Idea: I shall beg off talking of a) whether genera and species are real or situated in bare thoughts alone, b) whether as real they are bodies or incorporeals, and c) whether they are separated or in sensibles and have their reality in connection with them. | |
| From: Porphyry (Isagoge ('Introduction') [c.295], (2)) | |
| A reaction: This passage, picking up on Aristotle, seems to be the original source that grew into the medievel debate about universals. It seems to rather neatly lay out the agenda for the universals debate which is still with us. |
| 74 | Even God could not undo what has been done [Agathon] |
| Full Idea: One thing is denied even to God: to make what has been done undone again. | |
| From: Agathon (plays (frags) [c.410 BCE]), quoted by Aristotle - Nicomachean Ethics 1139b09 | |
| A reaction: a quotation - cf the Euthyphro Question |