15 ideas
| 14782 | Philosophy is an experimental science, resting on common experience [Peirce] |
| 4187 | 'There is nothing without a reason why it should be rather than not be' (a generalisation of 'Why?') [Schopenhauer] |
| 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] |
| 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] |
| 4192 | All necessity arises from causation, which is conditioned; there is no absolute or unconditioned necessity [Schopenhauer] |
| 4190 | All understanding is an immediate apprehension of the causal relation [Schopenhauer] |
| 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] |
| 4191 | What we know in ourselves is not a knower but a will [Schopenhauer] |
| 21368 | The knot of the world is the use of 'I' to refer to both willing and knowing [Schopenhauer] |
| 14784 | Ethics is the science of aims [Peirce] |
| 19458 | Egoism is the only evil, love the only good; genuine love produces all the other virtues [Feuerbach] |
| 4189 | Time may be defined as the possibility of mutually exclusive conditions of the same thing [Schopenhauer] |