12 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] |
| 17807 | To study formal systems, look at the whole thing, and not just how it is constructed in steps [Curry] |
| 17806 | It is untenable that mathematics is general physical truths, because it needs infinity [Curry] |
| 14788 | Mathematics is close to logic, but is even more abstract [Peirce] |
| 17808 | Saying mathematics is logic is merely replacing one undefined term by another [Curry] |
| 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] |
| 18285 | All translation loses some content (but language does not create reality) [Carnap] |
| 14784 | Ethics is the science of aims [Peirce] |