display all the ideas for this combination of texts
5 ideas
| 16630 | If we perceive an attribute, we infer the existence of some substance [Descartes] |
| Full Idea: Based on perceiving the presence of some attribute, we conclude there must also be present an existing thing or substance to which it can be attributed. | |
| From: René Descartes (Principles of Philosophy [1646], I.52), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 08.1 | |
| A reaction: A rainbow might be a tricky case. This illustrates the persistent belief in substances, even among philosophers who embraced the new corpuscular and mechanistic view of matter. |
| 5013 | A substance needs nothing else in order to exist [Descartes] |
| Full Idea: By substance we can understand nothing else than a thing which so exists that it needs no other thing in order to exist. | |
| From: René Descartes (Principles of Philosophy [1646], I.51) | |
| A reaction: Properties, of course, are the things which have dependent existence. Can properties be reduced to substances (e.g. by adopting a materialist theory of mind)? Note that Descartes does not think that substances depend on God for existence. |
| 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. |
| 16633 | A substance has one principal property which is its nature and essence [Descartes] |
| Full Idea: Each substance has one principal property that constitutes its nature and essence, to which all its other properties are referred. Extension in length, breadth, and depth constitutes the nature of corporeal substance; and thought of thinking substances. | |
| From: René Descartes (Principles of Philosophy [1646], I.53), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 08.3 | |
| A reaction: Property is likely to be 'propria', which is a property distinctive of some thing, not just any old modern property. This is quite a strikingly original view of the nature of essence. Descartes despised 'substantial forms'. |
| 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? |