  During the eighteenth century the Principia was also seen as putting forward a world view directly in opposition to the broadly Cartesian world view that in many circles had taken over from the Scholastic world view during the second half of the seventeenth century. Newton clearly intended the work to be viewed in this way when in 1686 he changed its title to Philosophiae Naturalis Principia Mathematica, in allusion to Descartes's most prominent work at the time, Principia Philosophiae. (The title page of Newton's first edition underscored this allusion by placing the first and third words of the title in larger type.) The main difference in the world view in Newton's Principia was to rid the celestial spaces of vortices carrying the planets. Newtonians subsequently went beyond Newton in enhancing this world view in various ways, including forces everywhere expressly acting at a distance. The “clockwork universe” aspect of the Newtonian world view, for example, is not to be found in the Principia; it was added by Laplace late in the eighteenth century, after the success of the theory of gravity in accounting for complex deviations from Keplerian motion became fully evident.