display all the ideas for this combination of texts
2 ideas
| 19067 | A successful proof requires recognition of truth at every step [Dummett] |
| Full Idea: For a demonstration to be cogent it is necessary that the passage from step to step involve a recognition of truth at each line. | |
| From: Michael Dummett (The Justification of Deduction [1973], p.313) | |
| A reaction: Dummett cited Quine (esp. 1970) as having an almost entirely syntactic view of logic. Rumfitt points out that logic can move validly from one falsehood to another. Even a 'proof' might detour into falsehood, but it would not be a 'canonical' proof! |
| 5515 | Imaginary cases are good for revealing our beliefs, rather than the truth [Parfit] |
| Full Idea: I believe it is worth considering imaginary cases (such as Teletransportation), as we can use them to discover, not what the truth is, but what we believe. | |
| From: Derek Parfit (The Unimportance of Identity [1995], p.293) | |
| A reaction: The trouble is that we might say that IF I were suddenly turned into a pig, then I would come to believe in dualism, but that will not and cannot happen, because dualism is false. It seems essential to accept the natural possibility of the case. |