63 ideas
| 15413 | With four tense operators, all complex tenses reduce to fourteen basic cases [Burgess] |
| 15415 | The temporal Barcan formulas fix what exists, which seems absurd [Burgess] |
| 15430 | Is classical logic a part of intuitionist logic, or vice versa? [Burgess] |
| 15431 | It is still unsettled whether standard intuitionist logic is complete [Burgess] |
| 15429 | Relevance logic's → is perhaps expressible by 'if A, then B, for that reason' [Burgess] |
| 15404 | Technical people see logic as any formal system that can be studied, not a study of argument validity [Burgess] |
| 15405 | Classical logic neglects the non-mathematical, such as temporality or modality [Burgess] |
| 15421 | Classical logic neglects counterfactuals, temporality and modality, because maths doesn't use them [Burgess] |
| 15427 | The Cut Rule expresses the classical idea that entailment is transitive [Burgess] |
| 15403 | Philosophical logic is a branch of logic, and is now centred in computer science [Burgess] |
| 15407 | Formalising arguments favours lots of connectives; proving things favours having very few [Burgess] |
| 15424 | Asserting a disjunction from one disjunct seems odd, but can be sensible, and needed in maths [Burgess] |
| 15409 | All occurrences of variables in atomic formulas are free [Burgess] |
| 15414 | The denotation of a definite description is flexible, rather than rigid [Burgess] |
| 15406 | 'Induction' and 'recursion' on complexity prove by connecting a formula to its atomic components [Burgess] |
| 15425 | The sequent calculus makes it possible to have proof without transitivity of entailment [Burgess] |
| 15426 | We can build one expanding sequence, instead of a chain of deductions [Burgess] |
| 15408 | 'Tautologies' are valid formulas of classical sentential logic - or substitution instances in other logics [Burgess] |
| 15418 | Validity (for truth) and demonstrability (for proof) have correlates in satisfiability and consistency [Burgess] |
| 15411 | We only need to study mathematical models, since all other models are isomorphic to these [Burgess] |
| 15412 | Models leave out meaning, and just focus on truth values [Burgess] |
| 15416 | We aim to get the technical notion of truth in all models matching intuitive truth in all instances [Burgess] |
| 15428 | The Liar seems like a truth-value 'gap', but dialethists see it as a 'glut' [Burgess] |
| 12747 | Monads are not extended, but have a kind of situation in extension [Leibniz] |
| 12748 | Only monads are substances, and bodies are collections of them [Leibniz] |
| 13184 | The division of nature into matter makes distinct appearances, and that presupposes substances [Leibniz] |
| 13188 | The only indications of reality are agreement among phenomena, and their agreement with necessities [Leibniz] |
| 12752 | Only unities have any reality [Leibniz] |
| 13187 | In actual things nothing is indefinite [Leibniz] |
| 19383 | A man's distant wife dying is a real change in him [Leibniz] |
| 13179 | A complete monad is a substance with primitive active and passive power [Leibniz] |
| 12749 | Derivate forces are in phenomena, but primitive forces are in the internal strivings of substances [Leibniz] |
| 12722 | Thought terminates in force, rather than extension [Leibniz] |
| 19379 | The law of the series, which determines future states of a substance, is what individuates it [Leibniz] |
| 13182 | Changeable accidents are modifications of unchanging essences [Leibniz] |
| 13178 | Things in different locations are different because they 'express' those locations [Leibniz] |
| 19412 | If two bodies only seem to differ in their position, those different environments will matter [Leibniz] |
| 19411 | In nature there aren't even two identical straight lines, so no two bodies are alike [Leibniz] |
| 15420 | De re modality seems to apply to objects a concept intended for sentences [Burgess] |
| 15417 | Logical necessity has two sides - validity and demonstrability - which coincide in classical logic [Burgess] |
| 15419 | General consensus is S5 for logical modality of validity, and S4 for proof [Burgess] |
| 15423 | It is doubtful whether the negation of a conditional has any clear meaning [Burgess] |
| 15422 | Three conditionals theories: Materialism (material conditional), Idealism (true=assertable), Nihilism (no truth) [Burgess] |
| 19410 | Scientific truths are supported by mutual agreement, as well as agreement with the phenomena [Leibniz] |
| 7647 | The imagination alone perceives all objects; it is the soul, playing all its roles [La Mettrie] |
| 13183 | Primitive forces are internal strivings of substances, acting according to their internal laws [Leibniz] |
| 19409 | Soul represents body, but soul remains unchanged, while body continuously changes [Leibniz] |
| 7645 | When falling asleep, the soul becomes paralysed and weak, just like the body [La Mettrie] |
| 23225 | The soul's faculties depend on the brain, and are simply the brain's organisation [La Mettrie] |
| 7652 | Man is a machine, and there exists only one substance, diversely modified [La Mettrie] |
| 7650 | All thought is feeling, and rationality is the sensitive soul contemplating reasoning [La Mettrie] |
| 7651 | With wonderful new machines being made, a speaking machine no longer seems impossible [La Mettrie] |
| 11873 | Our notions may be formed from concepts, but concepts are formed from things [Leibniz] |
| 13186 | Universals are just abstractions by concealing some of the circumstances [Leibniz] |
| 7648 | The sun and rain weren't made for us; they sometimes burn us, or spoil our seeds [La Mettrie] |
| 13185 | Even if extension is impenetrable, this still offers no explanation for motion and its laws [Leibniz] |
| 13177 | An entelechy is a law of the series of its event within some entity [Leibniz] |
| 13093 | The only permanence in things, constituting their substance, is a law of continuity [Leibniz] |
| 13096 | The force behind motion is like a soul, with its own laws of continual change [Leibniz] |
| 13180 | Space is the order of coexisting possibles [Leibniz] |
| 13181 | Time is the order of inconsistent possibilities [Leibniz] |
| 7646 | There is no abrupt transition from man to animal; only language has opened a gap [La Mettrie] |
| 7649 | There is no clear idea of the soul, which should only refer to our thinking part [La Mettrie] |