19 ideas
| 14782 | Philosophy is an experimental science, resting on common experience [Peirce] |
| 14787 | Self-contradiction doesn't reveal impossibility; it is inductive impossibility which reveals self-contradiction [Peirce] |
| 14783 | Logic, unlike mathematics, is not hypothetical; it asserts categorical ends from hypothetical means [Peirce] |
| 4975 | A thought can be split in many ways, so that different parts appear as subject or predicate [Frege] |
| 9949 | There is the concept, the object falling under it, and the extension (a set, which is also an object) [Frege, by George/Velleman] |
| 14788 | Mathematics is close to logic, but is even more abstract [Peirce] |
| 18995 | Frege mistakenly takes existence to be a property of concepts, instead of being about things [Frege, by Yablo] |
| 10317 | It is unclear whether Frege included qualities among his abstract objects [Frege, by Hale] |
| 10535 | Frege's 'objects' are both the referents of proper names, and what predicates are true or false of [Frege, by Dummett] |
| 14786 | Some logical possibility concerns single propositions, but there is also compatibility between propositions [Peirce] |
| 14789 | Experience is indeed our only source of knowledge, provided we include inner experience [Peirce] |
| 14785 | The world is one of experience, but experiences are always located among our ideas [Peirce] |
| 9839 | Frege equated the concepts under which an object falls with its properties [Frege, by Dummett] |
| 4973 | As I understand it, a concept is the meaning of a grammatical predicate [Frege] |
| 9167 | Frege felt that meanings must be public, so they are abstractions rather than mental entities [Frege, by Putnam] |
| 4974 | For all the multiplicity of languages, mankind has a common stock of thoughts [Frege] |
| 14784 | Ethics is the science of aims [Peirce] |
| 1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
| 5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |