Questions on Newton, Mill and Duhem


1.  Does Newton reject Descartes' notion of a mechanical explanation or does he modify it?  Can Newton's views be regarded as a compromise between Descartes and Aritotle?  How are forces like or unlike Aristotle's internal principles of motion?

2.  What does Newton notice about the image produced by a prism?  What leads him to notice it?

3.  Why does Newton deny that his account of colors is a hypothesis?  What does he mean by a "hypothesis"?

4.  How does Hooke's approach to theorizing concerning the phenomena of colors differ?  How does Hooke misunderstand Newton?

5.  What sort of certainty does Newton claim for his conclusions?  In what sense has optics been made a mathematical science?

6.  How does Newton distinguish his attribution of gravity to bodies from Aristotle's attribution of forms or internal principles of motion?  Duhem quotes Descartes as writing, "Nothing is more absurd than the assumption. . .that a certain property is inherent in each of the parts of the world's matter and that, by the force of this property, the parts are carried toward one another and attract each other.. . .In order to understand this, we must not only assume that each material particle is animated, and even animated by a large number of diverse souls that do not disturb each other, but also that these souls of material particles are endowed with knowledge of a truly divine sort, so that they may know without any medium what takes place at very great distances and act accordingly" (Aim and Structure, pp. 15-16).  How does Newton respond?

7.  Mill writes, "The word explanation is here used in its philosophical sense.  What is called explaining one law of nature by another, is but substituting one mystery for another, and does nothing to render the general course of nature other than mysterious: we can no more assign a why for the most extensive laws than for the partial ones."  Would Aristotle, Descartes, Newton, and Duhem agree?

8.  Newton writes (on page 2 of the reprint of his letter to Oldenburg) "And so the true cause of the length of the image was detected to be no other than that light consists of rays differently refrangible, which . . . were according to their degrees of refrangibility, transmitted toward diverse parts of the wall." [my italics]  Does this explain why prisms split white light into colors, why the colors lie in bands, and so forth?  What do you think?  What would Aristotle, Descartes, Mill, and Duhem say?

9. How are we to understand Duhem's view that science should not aim at giving explanations?  What does he take an explanation to require?  Why, in his view, do explanations inevitably involve metaphysics?  Do physical theories fail to be explanations because they are not true or because their principles fail to satisfy metaphysical constraints?