35 ideas
| 1798 | He studied philosophy by suspending his judgement on everything [Pyrrho, by Diog. Laertius] |
| 23657 | The existence of tensed verbs shows that not all truths are necessary truths [Reid] |
| 1800 | Sceptics say reason is only an instrument, because reason can only be attacked with reason [Pyrrho, by Diog. Laertius] |
| 23655 | An ad hominem argument is good, if it is shown that the man's principles are inconsistent [Reid] |
| 21695 | The set scheme discredited by paradoxes is actually the most natural one [Quine] |
| 21693 | Russell's antinomy challenged the idea that any condition can produce a set [Quine] |
| 21691 | Antinomies contradict accepted ways of reasoning, and demand revisions [Quine] |
| 21690 | Whenever the pursuer reaches the spot where the pursuer has been, the pursued has moved on [Quine] |
| 21689 | A barber shaves only those who do not shave themselves. So does he shave himself? [Quine] |
| 21694 | Membership conditions which involve membership and non-membership are paradoxical [Quine] |
| 21692 | If we write it as '"this sentence is false" is false', there is no paradox [Quine] |
| 23659 | If someone denies that he is thinking when he is conscious of it, we can only laugh [Reid] |
| 23662 | The existence of ideas is no more obvious than the existence of external objects [Reid] |
| 23661 | We are only aware of other beings through our senses; without that, we are alone in the universe [Reid] |
| 23654 | In obscure matters the few must lead the many, but the many usually lead in common sense [Reid] |
| 23660 | The theory of ideas, popular with philosophers, means past existence has to be proved [Reid] |
| 6595 | If we need a criterion of truth, we need to know whether it is the correct criterion [Pyrrho, by Fogelin] |
| 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] |
| 1801 | Animals vary in their feelings and judgements (Mode 1) [Pyrrho, by Diog. Laertius] |
| 1803 | Objects vary according to which sense perceives them (Mode 3) [Pyrrho, by Diog. Laertius] |
| 1809 | Perception is affected by expectations (Mode 9) [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] |
| 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] |
| 1808 | Perception of things depends on their size or quantity (Mode 8) [Pyrrho, by Diog. Laertius] |
| 1804 | Perception varies with madness or disease (Mode 4) [Pyrrho, by Diog. Laertius] |
| 1806 | Perception of objects depends on surrounding conditions (Mode 6) [Pyrrho, by Diog. Laertius] |
| 23658 | Consciousness is an indefinable and unique operation [Reid] |
| 23656 | The structure of languages reveals a uniformity in basic human opinions [Reid] |
| 23653 | If you can't distinguish the features of a complex object, your notion of it would be a muddle [Reid] |
| 23663 | There are axioms of taste - such as a general consensus about a beautiful face [Reid] |
| 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] |