7 ideas
18170 | The Axiom of Reducibility is self-effacing: if true, it isn't needed [Quine] |
Full Idea: The Axiom of Reducibility is self-effacing: if it is true, the ramification it is meant to cope with was pointless to begin with. | |
From: Willard Quine (Introduction to Russell's Theory of Types [1967], p.152), quoted by Penelope Maddy - Naturalism in Mathematics I.1 | |
A reaction: Maddy says the rejection of Reducibility collapsed the ramified theory of types into the simple theory. |
16678 | Without magnitude a thing would retain its parts, but they would have no location [Buridan] |
Full Idea: If magnitude were removed from matter by divine power, it would still have parts distinct from one another, but they would not be positioned either outside one another or inside one another, because position would be removed. | |
From: Jean Buridan (Questions on Aristotle's Physics [1346], I.8 f. 11va), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 14.4 | |
A reaction: This shows why Quantity is such an important category for scholastic philosopher. |
16793 | A thing is (less properly) the same over time if each part is succeeded by another [Buridan] |
Full Idea: Less properly, one thing is said to be numerically the same as another according to the continuity of distinct parts, one in succession after another. In this way the Seine is said to be the same river after a thousand years. | |
From: Jean Buridan (Questions on Aristotle's Physics [1346], I.10, f. 13vb), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 29.3 | |
A reaction: This is a rather good solution to the difficulty of the looser non-transitive notion of a thing being 'the same'. The Ship of Theseus endures (in the simple case) as long as you remember to replace each departing plank. Must some parts be originals? |
16577 | Induction is not demonstration, because not all of the instances can be observed [Buridan] |
Full Idea: Inductions are not demonstrations, because they do not conclude on account of their form, since it is not possible to make an induction from all cases. | |
From: Jean Buridan (Questions on Aristotle's Physics [1346], I.15 f. 18vb), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 02.3 | |
A reaction: Thus showing that demonstration really is meant to be as conclusive as a mathematical proof, and that Aristotle seems to think such a thing is possible in physical science. |
16576 | Science is based on induction, for general truths about fire, rhubarb and magnets [Buridan] |
Full Idea: Induction should be regarded as a principle of natural science. For otherwise you could not prove that every fire is hot, that all rhubarb is purgative of bile, that every magnet attracts iron. | |
From: Jean Buridan (Questions on Aristotle's Physics [1346], I.15 f. 18vb), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 02.3 | |
A reaction: He is basing this on Aristotle, and refers to 'Physics' 190a33-b11. |
22442 | If lies were ever acceptable, with would undermine all duties based on contract [Kant] |
Full Idea: Truthfulness is a duty that must be regarded as the basis of all duties to be grounded on a contract, the law of which is made uncertain and useless if even the least exception to it is admitted. | |
From: Immanuel Kant (On a supposed right to lie [1797], p.30) | |
A reaction: Should we keep contracts which are made by means of deception and coercion? Where could such absolute authority for contracts come from? Do contracts and treaties tend to lapse after a long period of time? |
22441 | The law will protect you if you tell a truth which results in murder [Kant] |
Full Idea: If you have by a lie prevented someone bent on murder from committing the deed, then you are legally accountable for all the consequences that might arise from it. But if you keep strictly to the truth, then public justice can hold nothing against you. | |
From: Immanuel Kant (On a supposed right to lie [1797], p.29) | |
A reaction: Shocking, from a supposedly great thinker. Cowardly hiding behind a perverse law. What would Kant do if the law were changed, to condemn someone who told a truth which would probably lead to a murder? Would he accept a jail sentence? |