30 ideas
| 1798 | He studied philosophy by suspending his judgement on everything [Pyrrho, by Diog. Laertius] |
| 9271 | Human knowledge may not produce well-being; the examined life may not be worth living [Gray] |
| 1800 | Sceptics say reason is only an instrument, because reason can only be attacked with reason [Pyrrho, by Diog. Laertius] |
| 8920 | Equivalence relations are reflexive, symmetric and transitive, and classify similar objects [Lipschutz] |
| 6595 | If we need a criterion of truth, we need to know whether it is the correct criterion [Pyrrho, by Fogelin] |
| 9275 | Knowledge does not need minds or nervous systems; it is found in all living things [Gray] |
| 6593 | The Pyrrhonians attacked the dogmas of professors, not ordinary people [Pyrrho, by Fogelin] |
| 6592 | Academics said that Pyrrhonians were guilty of 'negative dogmatism' [Pyrrho, by Fogelin] |
| 1808 | Perception of things depends on their size or quantity (Mode 8) [Pyrrho, by Diog. Laertius] |
| 1802 | Individuals vary in responses and feelings (Mode 2) [Pyrrho, by Diog. Laertius] |
| 1807 | Perception varies with viewing distance and angle (Mode 7) [Pyrrho, by Diog. Laertius] |
| 1803 | Objects vary according to which sense perceives them (Mode 3) [Pyrrho, by Diog. Laertius] |
| 1806 | Perception of objects depends on surrounding conditions (Mode 6) [Pyrrho, by Diog. Laertius] |
| 1804 | Perception varies with madness or disease (Mode 4) [Pyrrho, by Diog. Laertius] |
| 1810 | Perception and judgement depend on comparison (Mode 10) [Pyrrho, by Diog. Laertius] |
| 1805 | Judgements vary according to local culture and law (Mode 5) [Pyrrho, by Diog. Laertius] |
| 1809 | Perception is affected by expectations (Mode 9) [Pyrrho, by Diog. Laertius] |
| 1801 | Animals vary in their feelings and judgements (Mode 1) [Pyrrho, by Diog. Laertius] |
| 9276 | The will hardly ever does anything; most of our life just happens to us [Gray] |
| 9278 | Nowadays we identify the free life with the good life [Gray] |
| 3062 | There are no causes, because they are relative, and alike things can't cause one another [Pyrrho, by Diog. Laertius] |
| 3063 | Motion can't move where it is, and can't move where it isn't, so it can't exist [Pyrrho, by Diog. Laertius] |
| 9280 | Over forty percent of the Earth's living tissue is human [Gray] |
| 23061 | Free atheism should start by questioning its faith in humanity [Gray] |
| 23057 | Gnosticism has a supreme creator God, giving way to a possibly hostile Demiurge [Gray] |
| 23056 | Judaism only became monotheistic around 550 BCE [Gray] |
| 9272 | Without Christianity we lose the idea that human history has a meaning [Gray] |
| 9279 | What was our original sin, and how could Christ's suffering redeem it? [Gray] |
| 23055 | Christians introduced the idea that a religion needs a creed [Gray] |
| 23058 | Buddhism has no divinity or souls, and the aim is to lose the illusion of a self [Gray] |