48 ideas
| 6420 | Only by analysing is progress possible in philosophy [Russell] |
| 6432 | Analysis gives new knowledge, without destroying what we already have [Russell] |
| 18781 | Inconsistency doesn't prevent us reasoning about some system [Mares] |
| 6437 | The theory of types makes 'Socrates and killing are two' illegitimate [Russell] |
| 6442 | Truth belongs to beliefs, not to propositions and sentences [Russell] |
| 18789 | Intuitionist logic looks best as natural deduction [Mares] |
| 18790 | Intuitionism as natural deduction has no rule for negation [Mares] |
| 18787 | Three-valued logic is useful for a theory of presupposition [Mares] |
| 6436 | I gradually replaced classes with properties, and they ended as a symbolic convenience [Russell] |
| 18793 | Material implication (and classical logic) considers nothing but truth values for implications [Mares] |
| 18784 | In classical logic the connectives can be related elegantly, as in De Morgan's laws [Mares] |
| 18786 | Excluded middle standardly implies bivalence; attacks use non-contradiction, De M 3, or double negation [Mares] |
| 18780 | Standard disjunction and negation force us to accept the principle of bivalence [Mares] |
| 7528 | Leibniz bases everything on subject/predicate and substance/property propositions [Russell] |
| 18782 | The connectives are studied either through model theory or through proof theory [Mares] |
| 6439 | Names are meaningless unless there is an object which they designate [Russell] |
| 18783 | Many-valued logics lack a natural deduction system [Mares] |
| 18792 | Situation semantics for logics: not possible worlds, but information in situations [Mares] |
| 18785 | Consistency is semantic, but non-contradiction is syntactic [Mares] |
| 6423 | We tried to define all of pure maths using logical premisses and concepts [Russell] |
| 6424 | Formalists say maths is merely conventional marks on paper, like the arbitrary rules of chess [Russell] |
| 6425 | Formalism can't apply numbers to reality, so it is an evasion [Russell] |
| 6426 | Intuitionism says propositions are only true or false if there is a method of showing it [Russell] |
| 18788 | For intuitionists there are not numbers and sets, but processes of counting and collecting [Mares] |
| 22227 | For Sartre there is only being for-itself, or being in-itself (which is beyond experience) [Sartre, by Daigle] |
| 6419 | In 1899-1900 I adopted the philosophy of logical atomism [Russell] |
| 6438 | Complex things can be known, but not simple things [Russell] |
| 6434 | Facts are everything, except simples; they are either relations or qualities [Russell] |
| 6440 | Universals can't just be words, because words themselves are universals [Russell] |
| 6430 | In epistemology we should emphasis the continuity between animal and human minds [Russell] |
| 20743 | Appearances do not hide the essence; appearances are the essence [Sartre] |
| 6441 | Pragmatism judges by effects, but I judge truth by causes [Russell] |
| 6431 | Empiricists seem unclear what they mean by 'experience' [Russell] |
| 6444 | True belief about the time is not knowledge if I luckily observe a stopped clock at the right moment [Russell] |
| 6151 | Sartre says consciousness is just directedness towards external objects [Sartre, by Rowlands] |
| 6433 | Behaviourists struggle to explain memory and imagination, because they won't admit images [Russell] |
| 6443 | Surprise is a criterion of error [Russell] |
| 6164 | Sartre rejects mental content, and the idea that the mind has hidden inner features [Sartre, by Rowlands] |
| 6427 | Unverifiable propositions about the remote past are still either true or false [Russell] |
| 18791 | In 'situation semantics' our main concepts are abstracted from situations [Mares] |
| 6435 | You can believe the meaning of a sentence without thinking of the words [Russell] |
| 7074 | Man is a useless passion [Sartre] |
| 6687 | Man is the desire to be God [Sartre] |
| 22228 | Sartre's freedom is not for whimsical action, but taking responsibility for our own values [Sartre, by Daigle] |
| 22233 | Love is the demand to be loved [Sartre] |
| 20755 | Fear concerns the world, but 'anguish' comes from confronting my self [Sartre] |
| 20760 | Sincerity is not authenticity, because it only commits to one particular identity [Sartre, by Aho] |
| 22231 | We flee from the anguish of freedom by seeing ourselves objectively, as determined [Sartre] |