7 ideas
| 13007 | Archimedes defined a straight line as the shortest distance between two points [Archimedes, by Leibniz] |
| Full Idea: Archimedes gave a sort of definition of 'straight line' when he said it is the shortest line between two points. | |
| From: report of Archimedes (fragments/reports [c.240 BCE]) by Gottfried Leibniz - New Essays on Human Understanding 4.13 | |
| A reaction: Commentators observe that this reduces the purity of the original Euclidean axioms, because it involves distance and measurement, which are absent from the purest geometry. |
| 14633 | How do we tell a table's being contingently plastic from its being essentially plastic? [Jackson] |
| Full Idea: On a friendly reading of Quine, there is nothing to make the difference between a table's being contingently plastic and its being essentially plastic. | |
| From: Frank Jackson (Possible Worlds and Necessary A Posteriori [2010], 5) | |
| A reaction: This is, of course, the dreaded modern usage of 'essential' to just mean 'necessary' and nothing more. In my view, there may be a big problem with knowing whether a problem is necessary, but knowing whether it is essential is much easier. |
| 14635 | An x is essentially F if it is F in every possible world in which it appears [Jackson] |
| Full Idea: On the possible world's account, x's being essentially F is nothing more nor less than x's being F in every world in which it appears. | |
| From: Frank Jackson (Possible Worlds and Necessary A Posteriori [2010], 6) | |
| A reaction: There you go - 'true in every possible world' is the definition of metaphysical necessity, not the definition of essence. Either get back to Aristotle, or stop (forever!) talking about 'essence'! |
| 14632 | Quine may have conflated de re and de dicto essentialism, but there is a real epistemological problem [Jackson] |
| Full Idea: The unfriendly response to Quine's objection to essentialism is that it conflates the de re and the de dicto. The friendly response is that behind that conflation is a real epistemological problem for essentialism. | |
| From: Frank Jackson (Possible Worlds and Necessary A Posteriori [2010], 1) | |
| A reaction: He cites Richard Cartwright 1968 for the friendly response. The epistemological question is how we can know the essentialness of an essence. |
| 14631 | How can you show the necessity of an a posteriori necessity, if it might turn out to be false? [Jackson] |
| Full Idea: If something is offered as a candidate necessary a posteriori truth, how could we show that it is necessary, in the face of the fact that it takes investigation to show that it is true, and so, in some sense, it might have turned out to be false? | |
| From: Frank Jackson (Possible Worlds and Necessary A Posteriori [2010], 1) | |
| A reaction: This is the topic of his paper, which he compares with how we can know that essences are essential. |
| 20594 | Choosers in the 'original position' have been stripped of most human characteristics [Sandel, by Tuckness/Wolf] |
| Full Idea: Sandel argues that people in the 'original position' have been stripped of everything that makes them recognisably human: their conceptions of the good, their nationality, family membership, religion, friendships and past histories. | |
| From: report of Michael J. Sandel (Liberalism and the Limits of Justice [1982]) by Tuckness,A/Wolf,C - This is Political Philosophy 4 'Communitarian' | |
| A reaction: This draws attention to what a pure Enlightenment rational project Rawls is pursuing, in the spirit if Kant's ethics. Choosers in the original position become identical, and thus choose a homogeneous society. |
| 21120 | The self is 'unencumbered' if it can abandon its roles and commitments without losing identity [Sandel, by Shorten] |
| Full Idea: Sandel says liberals are committed to the 'unencumbered self', ..when it has no roles, commitments or projects that are 'so essential that turning away from them would call into question the person I am'. | |
| From: report of Michael J. Sandel (Liberalism and the Limits of Justice [1982], p.86) by Andrew Shorten - Contemporary Political Theory 02 | |
| A reaction: This is a very penetrating criticism of liberalism. The liberal self that makes social and legal contracts and exercises basic political rights is not far from being a robot. It has the minimum needed to join a society. Belonging is quite different. |