The main point of this paper is to identify a set of interlocking views that became (and still are!) very influential within philosophy in the wake of Newton’s success. These views use the authority of natural philosophy/mechanics to settle debates within philosophy. I label these “Newton’s Challenge.” Newton had some hand in promoting them, but he is not responsible for all of them. My paper, thus, revisits an old theme articulated by A.E. Burt, but I offer new arguments and evidence. The heart of the paper (sections II-III) identifies the core set of related views that constitute “Newton’s Challenge.” In section IIA I draw on two eighteenth century figures (Euler and Musschenbroek) to introduce arguments that give evidence for the existence of “Newton’s Challenge” and distinguish four strands within it. In section IIB I use Berkeley as evidence that something like “Newton’s Challenge” was recognized by philosophical opponents to Newton and I identify in Berkeley’s work five counter-strategies. In section IIC, I identify Newton’s contribution to Newton’s Challenge. In section III, I use the writings by MacLaurin, ’s Gravesande, and Musschenbroek to identify eight arguments that constitute the way “Newton’s Challenge” was articulated and developed in practice by eighteenth century Newtonians.