5 ideas
11074 | 'It is true that this follows' means simply: this follows [Wittgenstein] |
Full Idea: The proposition: "It is true that this follows from that" means simply: this follows from that. | |
From: Ludwig Wittgenstein (Remarks on the Foundations of Mathematics [1938], p.38), quoted by Robert Hanna - Rationality and Logic 6 | |
A reaction: Presumably this remark is simply expressing Wittgenstein's later agreement with the well-known view of Ramsey. Early Wittgenstein had endorsed a correspondence view of truth. |
11073 | Two and one making three has the necessity of logical inference [Wittgenstein] |
Full Idea: "But doesn't it follow with logical necessity that you get two when you add one to one, and three when you add one to two? and isn't this inexorability the same as that of logical inference? - Yes! it is the same. | |
From: Ludwig Wittgenstein (Remarks on the Foundations of Mathematics [1938], p.38), quoted by Robert Hanna - Rationality and Logic 6 | |
A reaction: This need not be a full commitment to logicism - only to the fact that the inferential procedures in mathematics are the same as those of logic. Mathematics could still have further non-logical ingredients. Indeed, I think it probably does. |
21681 | Given all true atomic propositions, in theory every other truth can thereby be deduced [Russell] |
Full Idea: Given all true atomic propositions, together with the fact that they are all, every other true proposition can theoretically be deduced by logical methods. | |
From: Bertrand Russell (Intro to 2nd ed of Principia Mathematica [1925], p.xv) | |
A reaction: This is evidently his strongest statement of the ideal underlying logical atomism. The atoms were initially sense-date, but then became atomic propositions saying an object has a property. |
16713 | Philosophers are the forefathers of heretics [Tertullian] |
Full Idea: Philosophers are the forefathers of heretics. | |
From: Tertullian (works [c.200]), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 20.2 |
6610 | I believe because it is absurd [Tertullian] |
Full Idea: I believe because it is absurd ('Credo quia absurdum est'). | |
From: Tertullian (works [c.200]), quoted by Robert Fogelin - Walking the Tightrope of Reason n4.2 | |
A reaction: This seems to be a rather desperate remark, in response to what must have been rather good hostile arguments. No one would abandon the support of reason if it was easy to acquire. You can't deny its engaging romantic defiance, though. |