13 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] |
| 23476 | Logical constants seem to be entities in propositions, but are actually pure form [Russell] |
| 23477 | We use logical notions, so they must be objects - but I don't know what they really are [Russell] |
| 18273 | Logical truths are known by their extreme generality [Russell] |
| 14788 | Mathematics is close to logic, but is even more abstract [Peirce] |
| 22315 | There can't be a negative of a complex, which is negated by its non-existence [Potter on Russell] |
| 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] |
| 14784 | Ethics is the science of aims [Peirce] |
| 5994 | Is the cosmos open or closed, mechanical or teleological, alive or inanimate, and created or eternal? [Robinson,TM, by PG] |