² Descartes, A Discourse on the Method of Correctly Conducting One’s Reason and Seeking Truth in the Sciences, ed. and trans. Ian Maclean, Oxford World’s Classics (Oxford: Oxford University Press, 2006), pp. viii, xli, xliii. All references to the Discourse are to this edition, which gives a very full account of the context and significance of the text. (I give first the Part of the text referred to, and then the page number, so that ii. 15 refers to Part II of the Discourse, the passage in question being found on p. 15.)