Combining Philosophers

All the ideas for Archimedes, Robert Grosseteste and Sphaerus

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3 ideas

6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry
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.
9. Objects / B. Unity of Objects / 2. Substance / b. Need for substance
16629 By comparing qualities and features, reason can gradually infer the nature of substance [Grosseteste]
     Full Idea: Awakened reason distinguishes color from size and shape from body and then shape and size from the substance of body, and so by drawing distinctions and abstracting, it arrives at a grasp of the substance of body, which supports size, shape and color.
     From: Robert Grosseteste (Commentary on 'Posterior Analytics' [1226], I.14), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 07.4
     A reaction: This optimistic view influenced Aquinas, and is called 'incrementalism' by Pasnau. It is the spirit of scientific essentialism, and a nice instance of inference to the best explanation (though 'substance' in itself explains virtually nothing).
13. Knowledge Criteria / A. Justification Problems / 2. Justification Challenges / c. Knowledge closure
20769 Sphaerus he was not assenting to the presence of pomegranates, but that it was 'reasonable' [Sphaerus, by Diog. Laertius]
     Full Idea: When Sphaerus accepted pomegranates from the king, he was accused of assenting to a false presentation, to which Sphaerus replied that what he had assented to was not that they were pomegranates, but that it was reasonable that they were pomegranates.
     From: report of Sphaerus (fragments/reports [c.240 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 07.177
     A reaction: He then cited the stoic distinction between a 'graspable' presentation and a 'reasonable' one. This seems a rather helpful response to Dretske's zebra problem. I like the word 'sensible' in epistemology, because animals can be sensible.