20 ideas
| 291 | Don't assume that wisdom is the automatic consequence of old age [Plato] |
| 17641 | Discoveries in mathematics can challenge philosophy, and offer it a new foundation [Russell] |
| 17638 | If one proposition is deduced from another, they are more certain together than alone [Russell] |
| 17632 | Non-contradiction was learned from instances, and then found to be indubitable [Russell] |
| 17629 | Which premises are ultimate varies with context [Russell] |
| 17630 | The sources of a proof are the reasons why we believe its conclusion [Russell] |
| 17640 | Finding the axioms may be the only route to some new results [Russell] |
| 17627 | It seems absurd to prove 2+2=4, where the conclusion is more certain than premises [Russell] |
| 17628 | Arithmetic was probably inferred from relationships between physical objects [Russell] |
| 12312 | The real essence of a thing is its powers, or 'dispositional properties' [Copi] |
| 10937 | Essential properties are the 'deepest' ones which explain the others [Copi, by Rami] |
| 12308 | In modern science, nominal essence is intended to be real essence [Copi] |
| 12303 | Within the four types of change, essential attributes are those whose loss means destruction [Copi] |
| 17637 | The most obvious beliefs are not infallible, as other obvious beliefs may conflict [Russell] |
| 17639 | Believing a whole science is more than believing each of its propositions [Russell] |
| 17631 | Induction is inferring premises from consequences [Russell] |
| 293 | Being unafraid (perhaps through ignorance) and being brave are two different things [Plato] |
| 17633 | The law of gravity has many consequences beyond its grounding observations [Russell] |
| 12307 | Modern science seeks essences, and is getting closer to them [Copi] |
| 12310 | Real essences are scientifically knowable, but so are non-essential properties [Copi] |