24 ideas
5784 | In its primary and formal sense, 'true' applies to propositions, not beliefs [Russell] |
5777 | The truth or falsehood of a belief depends upon a fact to which the belief 'refers' [Russell] |
5783 | Propositions of existence, generalities, disjunctions and hypotheticals make correspondence tricky [Russell] |
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] |
10159 | Löwenheim-Skolem Theorem, and Gödel's completeness of first-order logic, the earliest model theory [Feferman/Feferman] |
10160 | Löwenheim-Skolem says if the sentences are countable, so is the model [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] |
19400 | Possibles demand existence, so as many of them as possible must actually exist [Leibniz] |
19401 | God's sufficient reason for choosing reality is in the fitness or perfection of possibilities [Leibniz] |
19402 | The actual universe is the richest composite of what is possible [Leibniz] |
5780 | The three questions about belief are its contents, its success, and its character [Russell] |
5778 | If we object to all data which is 'introspective' we will cease to believe in toothaches [Russell] |
5779 | There are distinct sets of psychological and physical causal laws [Russell] |
5781 | Our important beliefs all, if put into words, take the form of propositions [Russell] |
5782 | A proposition expressed in words is a 'word-proposition', and one of images an 'image-proposition' [Russell] |
5776 | A proposition is what we believe when we believe truly or falsely [Russell] |