19 ideas
8000 | He who is ignorant of the history of philosophy is doomed to repeat it [Santayana, by MacIntyre] |
6222 | If a decision is in accord with right reason, everyone can agree with it [Cumberland] |
10757 | Henkin semantics has a second domain of predicates and relations (in upper case) [Rossberg] |
10751 | Second-order logic needs the sets, and its consequence has epistemological problems [Rossberg] |
10759 | There are at least seven possible systems of semantics for second-order logic [Rossberg] |
10753 | Logical consequence is intuitively semantic, and captured by model theory [Rossberg] |
10752 | Γ |- S says S can be deduced from Γ; Γ |= S says a good model for Γ makes S true [Rossberg] |
10754 | In proof-theory, logical form is shown by the logical constants [Rossberg] |
10756 | A model is a domain, and an interpretation assigning objects, predicates, relations etc. [Rossberg] |
10758 | If models of a mathematical theory are all isomorphic, it is 'categorical', with essentially one model [Rossberg] |
10761 | Completeness can always be achieved by cunning model-design [Rossberg] |
10755 | A deductive system is only incomplete with respect to a formal semantics [Rossberg] |
18521 | The criterion of existence is the possibility of action [Santayana] |
6217 | Natural law is supplied to the human mind by reality and human nature [Cumberland] |
23060 | The good is not relative, but is rooted in facts about human needs [Santayana] |
6221 | If there are different ultimate goods, there will be conflicting good actions, which is impossible [Cumberland] |
6218 | The happiness of individuals is linked to the happiness of everyone (which is individuals taken together) [Cumberland] |
6220 | The happiness of all contains the happiness of each, and promotes it [Cumberland] |
6216 | Natural law is immutable truth giving moral truths and duties independent of society [Cumberland] |