55 ideas
| 6602 | Philosophy is like a statue which is worshipped but never advances [Bacon] |
| 12124 | Metaphysics is the best knowledge, because it is the simplest [Bacon] |
| 12123 | Natural history supports physical knowledge, which supports metaphysical knowledge [Bacon] |
| 12119 | Physics studies transitory matter; metaphysics what is abstracted and necessary [Bacon] |
| 12120 | Physics is of material and efficient causes, metaphysics of formal and final causes [Bacon] |
| 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] |
| 15426 | We can build one expanding sequence, instead of a chain of deductions [Burgess] |
| 15425 | The sequent calculus makes it possible to have proof without transitivity of entailment [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] |
| 10185 | Set theory is the standard background for modern mathematics [Burgess] |
| 10184 | Structuralists take the name 'R' of the reals to be a variable ranging over structures, not a structure [Burgess] |
| 10189 | There is no one relation for the real number 2, as relations differ in different models [Burgess] |
| 10186 | If set theory is used to define 'structure', we can't define set theory structurally [Burgess] |
| 10187 | Abstract algebra concerns relations between models, not common features of all the models [Burgess] |
| 10188 | How can mathematical relations be either internal, or external, or intrinsic? [Burgess] |
| 16639 | Only individual bodies exist [Bacon] |
| 16625 | In hylomorphism all the explanation of actions is in the form, and the matter doesn't do anything [Bacon] |
| 16033 | There are only individual bodies containing law-based powers, and the Forms are these laws [Bacon] |
| 12887 | A whole must have one characteristic, an internal relation, and a structure [Rescher/Oppenheim] |
| 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] |
| 15422 | Three conditionals theories: Materialism (material conditional), Idealism (true=assertable), Nihilism (no truth) [Burgess] |
| 15423 | It is doubtful whether the negation of a conditional has any clear meaning [Burgess] |
| 16724 | The senses deceive, but also show their own errors [Bacon] |
| 3648 | Empiricists are collecting ants; rationalists are spinning spiders; and bees do both [Bacon] |
| 12121 | We don't assume there is no land, because we can only see sea [Bacon] |
| 12117 | Science moves up and down between inventions of causes, and experiments [Bacon] |
| 6603 | Nature is revealed when we put it under pressure rather than observe it [Bacon] |
| 21950 | Science must clear away the idols of the mind if they are ever going to find the truth [Bacon] |
| 12127 | Many different theories will fit the observed facts [Bacon] |
| 12126 | People love (unfortunately) extreme generality, rather than particular knowledge [Bacon] |
| 12125 | Teleological accounts are fine in metaphysics, but they stop us from searching for the causes [Bacon] |
| 16624 | Stripped and passive matter is just a human invention [Bacon] |
| 12118 | Essences are part of first philosophy, but as part of nature, not part of logic [Bacon] |
| 7399 | Even without religion, there are many guides to morality [Bacon] |