30 ideas
| 18951 | For scientific purposes there is a precise concept of 'true-in-L', using set theory [Putnam] |
| 18953 | Modern notation frees us from Aristotle's restriction of only using two class-names in premises [Putnam] |
| 18949 | The universal syllogism is now expressed as the transitivity of subclasses [Putnam] |
| 18952 | '⊃' ('if...then') is used with the definition 'Px ⊃ Qx' is short for '¬(Px & ¬Qx)' [Putnam] |
| 18958 | In type theory, 'x ∈ y' is well defined only if x and y are of the appropriate type [Putnam] |
| 18954 | Before the late 19th century logic was trivialised by not dealing with relations [Putnam] |
| 18956 | Asserting first-order validity implicitly involves second-order reference to classes [Putnam] |
| 18962 | Unfashionably, I think logic has an empirical foundation [Putnam] |
| 18961 | We can identify functions with certain sets - or identify sets with certain functions [Putnam] |
| 18955 | Having a valid form doesn't ensure truth, as it may be meaningless [Putnam] |
| 20457 | Zeno assumes collecting an infinity of things makes an infinite thing [Rovelli] |
| 18959 | Sets larger than the continuum should be studied in an 'if-then' spirit [Putnam] |
| 20468 | Quantum mechanics deals with processes, rather than with things [Rovelli] |
| 20467 | Quantum mechanics describes the world entirely as events [Rovelli] |
| 18957 | Nominalism only makes sense if it is materialist [Putnam] |
| 18950 | Physics is full of non-physical entities, such as space-vectors [Putnam] |
| 18960 | Most predictions are uninteresting, and are only sought in order to confirm a theory [Putnam] |
| 13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
| 20469 | There are probably no infinities, and 'infinite' names what we do not yet know [Rovelli] |
| 20461 | The basic ideas of fields and particles are merged in quantum mechanics [Rovelli] |
| 20462 | Because it is quantised, a field behaves like a set of packets of energy [Rovelli] |
| 20463 | There are about fifteen particles fields, plus a few force fields [Rovelli] |
| 20464 | The world consists of quantum fields, with elementary events happening in spacetime [Rovelli] |
| 20460 | Electrons are not waves, because their collisions are at a point, and not spread out [Rovelli] |
| 20459 | Electrons only exist when they interact, and their being is their combination of quantum leaps [Rovelli] |
| 20466 | Quantum Theory describes events and possible interactions - not how things are [Rovelli] |
| 20465 | Nature has three aspects: granularity, indeterminacy, and relations [Rovelli] |
| 20458 | The world is just particles plus fields; space is the gravitational field [Rovelli] |
| 20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |
| 20470 | Only heat distinguishes past from future [Rovelli] |