16 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] |
| 2661 | Dialectic is speech cast in the form of logical argument [Cicero] |
| 2673 | There cannot be more than one truth [Cicero] |
| 14783 | Logic, unlike mathematics, is not hypothetical; it asserts categorical ends from hypothetical means [Peirce] |
| 2669 | Dialectic assumes that all statements are either true or false, but self-referential paradoxes are a big problem [Cicero] |
| 14788 | Mathematics is close to logic, but is even more abstract [Peirce] |
| 14786 | Some logical possibility concerns single propositions, but there is also compatibility between propositions [Peirce] |
| 2664 | If we have complete healthy senses, what more could the gods give us? [Cicero] |
| 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] |
| 2665 | How can there be a memory of what is false? [Cicero] |
| 20800 | Every true presentation can have a false one of the same quality [Cicero] |
| 22511 | Some reasonings are stronger than we are [Philolaus] |
| 14784 | Ethics is the science of aims [Peirce] |
| 2672 | Virtues must be very detached, to avoid being motivated by pleasure [Cicero] |