This chapter explains how the rise of the Mechanical philosophy during the seventeenth century contributed to the transformation of the traditional, Aristotelian schema of four causes into the dominance of efficient causation as the paradigmatic cause by the time of David Hume. But the chapter simultaneously shows that the mechanical philosophy also gave rise to a number of problems internal to it, as diagnosed by Newton and Newtonian natural philosophers, that facilitated more careful analysis of the nature of causation.