display all the ideas for this combination of texts
3 ideas
| 4195 | It is impossible to reach a valid false conclusion from true premises, so reason itself depends on possibility [Lowe] |
| Full Idea: Reasoning itself depends upon a grasp of possibilities, because a valid argument is one in which it is not possible for the conclusion to be false if the premises are true. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.11) | |
| A reaction: A very valuable corrective to my pessimistic view of philosophers' attempts to understand metaphysical necessity. But if we can only grasp natural necessity, then all reason is naturalistic. |
| 6181 | Necessity cannot be extracted from an empirical proposition [Kant] |
| Full Idea: It is a clear contradiction to try to extract necessity from an empirical proposition. | |
| From: Immanuel Kant (Critique of Practical Reason [1788], Pref) | |
| A reaction: This is precisely the idea which Kripke challenged, claiming that the necessary essences of natural kinds such as gold have to be discovered empirically. All my intuitions are with Kant (and Hume) on this, but it is a complex issue… |
| 4207 | We might eliminate 'possible' and 'necessary' in favour of quantification over possible worlds [Lowe] |
| Full Idea: It may be possible to eliminate the modal operators (in English, 'is possible' and 'is necessary') in favour of quantifier expressions with variables ranging over possible worlds. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.121) | |
| A reaction: Hence 'necessary' becomes 'exists/is true in all possible worlds'. Deep problems, but at least we must show that referring to 'possible' worlds isn't a circular explanation of 'is possible'. |