41 ideas
17749 | Post proved the consistency of propositional logic in 1921 [Walicki] |
17765 | Propositional language can only relate statements as the same or as different [Walicki] |
17764 | Boolean connectives are interpreted as functions on the set {1,0} [Walicki] |
17752 | The empty set is useful for defining sets by properties, when the members are not yet known [Walicki] |
17753 | The empty set avoids having to take special precautions in case members vanish [Walicki] |
17759 | Ordinals play the central role in set theory, providing the model of well-ordering [Walicki] |
17741 | To determine the patterns in logic, one must identify its 'building blocks' [Walicki] |
17747 | A 'model' of a theory specifies interpreting a language in a domain to make all theorems true [Walicki] |
17748 | The L-S Theorem says no theory (even of reals) says more than a natural number theory [Walicki] |
17761 | A compact axiomatisation makes it possible to understand a field as a whole [Walicki] |
17763 | Axiomatic systems are purely syntactic, and do not presuppose any interpretation [Walicki] |
17758 | Ordinals are transitive sets of transitive sets; or transitive sets totally ordered by inclusion [Walicki] |
17755 | Ordinals are the empty set, union with the singleton, and any arbitrary union of ordinals [Walicki] |
17756 | The union of finite ordinals is the first 'limit ordinal'; 2ω is the second... [Walicki] |
17760 | Two infinite ordinals can represent a single infinite cardinal [Walicki] |
17757 | Members of ordinals are ordinals, and also subsets of ordinals [Walicki] |
17762 | In non-Euclidean geometry, all Euclidean theorems are valid that avoid the fifth postulate [Walicki] |
17754 | Inductive proof depends on the choice of the ordering [Walicki] |
20339 | Classes rarely share properties with their members - unlike universals and types [Wollheim] |
17742 | Scotus based modality on semantic consistency, instead of on what the future could allow [Walicki] |
20338 | We often treat a type as if it were a sort of token [Wollheim] |
20342 | Interpretation is performance for some arts, and critical for all arts [Wollheim] |
20343 | A love of nature must precede a love of art [Wollheim] |
20348 | A criterion of identity for works of art would be easier than a definition [Wollheim] |
20347 | If beauty needs organisation, then totally simple things can't be beautiful [Wollheim] |
20345 | Some say art must have verbalisable expression, and others say the opposite! [Wollheim] |
20331 | It is claimed that the expressive properties of artworks are non-physical [Wollheim] |
20336 | Style can't be seen directly within a work, but appreciation needs a grasp of style [Wollheim] |
20337 | The traditional view is that knowledge of its genre to essential to appreciating literature [Wollheim] |
20333 | If artworks are not physical objects, they are either ideal entities, or collections of phenomena [Wollheim] |
20334 | The ideal theory says art is an intuition, shaped by a particular process, and presented in public [Wollheim] |
20335 | The ideal theory of art neglects both the audience and the medium employed [Wollheim] |
20340 | A musical performance has virtually the same features as the piece of music [Wollheim] |
20341 | An interpretation adds further properties to the generic piece of music [Wollheim] |
20332 | A drawing only represents Napoleon if the artist intended it to [Wollheim] |
3785 | You can't separate acts from the people performing them [Glover] |
3786 | Aggression in defence may be beneficial but morally corrupting [Glover] |
3784 | Duty prohibits some acts, whatever their consequences [Glover] |
3782 | Satisfaction of desires is not at all the same as achieving happiness [Glover, by PG] |
3787 | Rule-utilitarianism is either act-utilitarianism, or not really utilitarian [Glover] |
3783 | How can utilitarianism decide the ideal population size? [Glover] |