20 ideas
10147 | The Axiom of Choice is consistent with the other axioms of set theory [Feferman/Feferman] |
10148 | Axiom of Choice: a set exists which chooses just one element each of any set of sets [Feferman/Feferman] |
10149 | Platonist will accept the Axiom of Choice, but others want criteria of selection or definition [Feferman/Feferman] |
10150 | The Trichotomy Principle is equivalent to the Axiom of Choice [Feferman/Feferman] |
10146 | Cantor's theories needed the Axiom of Choice, but it has led to great controversy [Feferman/Feferman] |
10158 | A structure is a 'model' when the axioms are true. So which of the structures are models? [Feferman/Feferman] |
10162 | Tarski and Vaught established the equivalence relations between first-order structures [Feferman/Feferman] |
10160 | Löwenheim-Skolem says if the sentences are countable, so is the model [Feferman/Feferman] |
10159 | Löwenheim-Skolem Theorem, and Gödel's completeness of first-order logic, the earliest model theory [Feferman/Feferman] |
10161 | If a sentence holds in every model of a theory, then it is logically derivable from the theory [Feferman/Feferman] |
10156 | 'Recursion theory' concerns what can be solved by computing machines [Feferman/Feferman] |
10155 | Both Principia Mathematica and Peano Arithmetic are undecidable [Feferman/Feferman] |
5062 | First: there must be reasons; Second: why anything at all?; Third: why this? [Leibniz] |
19377 | A monad and its body are living, so life is everywhere, and comes in infinite degrees [Leibniz] |
19353 | 'Perception' is basic internal representation, and 'apperception' is reflective knowledge of perception [Leibniz] |
5061 | Animals are semi-rational because they connect facts, but they don't see causes [Leibniz] |
5063 | Music charms, although its beauty is the harmony of numbers [Leibniz] |
21093 | Friendship without community spirit misses out on the main part of virtue [Hume] |
21091 | It would be absurd if even a free constitution did not impose restraints, for the public good [Hume] |
21092 | Nobility either share in the power of the whole, or they compose the power of the whole [Hume] |