28 ideas
7807 | The laws of thought are true, but they are not the axioms of logic [Bolzano, by George/Van Evra] |
7791 | The simplest of the logics based on possible worlds is Lewis's S5 [Lewis,CI, by Girle] |
9987 | An aggregate in which order does not matter I call a 'set' [Bolzano] |
9358 | There are several logics, none of which will ever derive falsehoods from truth [Lewis,CI] |
9357 | Excluded middle is just our preference for a simplified dichotomy in experience [Lewis,CI] |
9364 | Names represent a uniformity in experience, or they name nothing [Lewis,CI] |
9618 | Bolzano wanted to reduce all of geometry to arithmetic [Bolzano, by Brown,JR] |
10856 | A truly infinite quantity does not need to be a variable [Bolzano] |
9830 | Bolzano began the elimination of intuition, by proving something which seemed obvious [Bolzano, by Dummett] |
17265 | Philosophical proofs in mathematics establish truths, and also show their grounds [Bolzano, by Correia/Schnieder] |
11002 | Equating necessity with informal provability is the S4 conception of necessity [Lewis,CI, by Read] |
9362 | Necessary truths are those we will maintain no matter what [Lewis,CI] |
7803 | Modal logic began with translation difficulties for 'If...then' [Lewis,CI, by Girle] |
9365 | We can maintain a priori principles come what may, but we can also change them [Lewis,CI] |
9185 | Bolzano wanted to avoid Kantian intuitions, and prove everything that could be proved [Bolzano, by Dummett] |
21500 | We rely on memory for empirical beliefs because they mutually support one another [Lewis,CI] |
21501 | If we doubt memories we cannot assess our doubt, or what is being doubted [Lewis,CI] |
6556 | If anything is to be probable, then something must be certain [Lewis,CI] |
21498 | Congruents assertions increase the probability of each individual assertion in the set [Lewis,CI] |
18088 | Intentionality is the mark of dispositions, not of the mental [Place] |
5828 | Extension is the class of things, intension is the correct definition of the thing, and intension determines extension [Lewis,CI] |
9361 | We have to separate the mathematical from physical phenomena by abstraction [Lewis,CI] |
22276 | Bolzano saw propositions as objective entities, existing independently of us [Bolzano, by Potter] |
17264 | Propositions are abstract structures of concepts, ready for judgement or assertion [Bolzano, by Correia/Schnieder] |
12232 | A 'proposition' is the sense of a linguistic expression, and can be true or false [Bolzano] |
12233 | The ground of a pure conceptual truth is only in other conceptual truths [Bolzano] |
9363 | Science seeks classification which will discover laws, essences, and predictions [Lewis,CI] |
18089 | Dispositions are not general laws, but laws of the natures of individual entities [Place] |