51 ideas
6420 | Only by analysing is progress possible in philosophy [Russell] |
6432 | Analysis gives new knowledge, without destroying what we already have [Russell] |
6437 | The theory of types makes 'Socrates and killing are two' illegitimate [Russell] |
6442 | Truth belongs to beliefs, not to propositions and sentences [Russell] |
9672 | Free logic is one of the few first-order non-classical logics [Priest,G] |
9697 | X1 x X2 x X3... x Xn indicates the 'cartesian product' of those sets [Priest,G] |
9685 | <a,b&62; is a set whose members occur in the order shown [Priest,G] |
9675 | a ∈ X says a is an object in set X; a ∉ X says a is not in X [Priest,G] |
9674 | {x; A(x)} is a set of objects satisfying the condition A(x) [Priest,G] |
9673 | {a1, a2, ...an} indicates that a set comprising just those objects [Priest,G] |
9677 | Φ indicates the empty set, which has no members [Priest,G] |
9676 | {a} is the 'singleton' set of a (not the object a itself) [Priest,G] |
9679 | X⊂Y means set X is a 'proper subset' of set Y [Priest,G] |
9678 | X⊆Y means set X is a 'subset' of set Y [Priest,G] |
9681 | X = Y means the set X equals the set Y [Priest,G] |
9683 | X ∩ Y indicates the 'intersection' of sets X and Y, the objects which are in both sets [Priest,G] |
9682 | X∪Y indicates the 'union' of all the things in sets X and Y [Priest,G] |
9684 | Y - X is the 'relative complement' of X with respect to Y; the things in Y that are not in X [Priest,G] |
9694 | The 'relative complement' is things in the second set not in the first [Priest,G] |
9693 | The 'intersection' of two sets is a set of the things that are in both sets [Priest,G] |
9692 | The 'union' of two sets is a set containing all the things in either of the sets [Priest,G] |
9698 | The 'induction clause' says complex formulas retain the properties of their basic formulas [Priest,G] |
9688 | A 'singleton' is a set with only one member [Priest,G] |
9687 | A 'member' of a set is one of the objects in the set [Priest,G] |
9695 | An 'ordered pair' (or ordered n-tuple) is a set with its members in a particular order [Priest,G] |
9696 | A 'cartesian product' of sets is the set of all the n-tuples with one member in each of the sets [Priest,G] |
9686 | A 'set' is a collection of objects [Priest,G] |
9689 | The 'empty set' or 'null set' has no members [Priest,G] |
9690 | A set is a 'subset' of another set if all of its members are in that set [Priest,G] |
9691 | A 'proper subset' is smaller than the containing set [Priest,G] |
9680 | The empty set Φ is a subset of every set (including itself) [Priest,G] |
6436 | I gradually replaced classes with properties, and they ended as a symbolic convenience [Russell] |
7528 | Leibniz bases everything on subject/predicate and substance/property propositions [Russell] |
6439 | Names are meaningless unless there is an object which they designate [Russell] |
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] |
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] |
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] |
6433 | Behaviourists struggle to explain memory and imagination, because they won't admit images [Russell] |
6443 | Surprise is a criterion of error [Russell] |
6427 | Unverifiable propositions about the remote past are still either true or false [Russell] |
6435 | You can believe the meaning of a sentence without thinking of the words [Russell] |
22489 | 'Good' is an attributive adjective like 'large', not predicative like 'red' [Geach, by Foot] |