  In common with the Renaissance, the early modern period was marked by a great concern with methodology. This might seem unsurprising in  such a revolutionary period, when new techniques for understanding  the world were being developed and that understanding itself was  being transformed. But what characterizes many of the treatises and  remarks on methodology that appeared in the seventeenth century is  their appeal, frequently self-conscious, to ancient methods (despite, or perhaps—for diplomatic reasons—because of, the  critique of the content of traditional thought), although  new wine was generally poured into the old bottles. The model of  geometrical analysis was a particular inspiration here, albeit  filtered through the Aristotelian tradition, which had assimilated  the regressive process of going from theorems to axioms with that of  moving from effects to causes (see the supplementary section on   Aristotle).  Analysis came to be seen as a method of discovery, working back from  what is ordinarily known to the underlying reasons (demonstrating  ‘the fact’), and synthesis as a method of proof, working  forwards again from what is discovered to what needed explanation  (demonstrating ‘the reason why’). Analysis and synthesis  were thus taken as complementary, although there remained  disagreement over their respective merits.