Principia philosophiae cartesianae (PPC; "The Principles of Cartesian Philosophy") or Renati Descartes principia philosophiae, more geometrico demonstrata ("The Principles of René Descartes' Philosophy, Demonstrated in Geometrical Order") is a philosophical work of Baruch Spinoza published in Amsterdam in 1663. In the preface to this work, Ludovic Meyer explains that it is a reconstruction of René Descartes' Principles of Philosophy in the Euclidean or "geometric" fashion. In the appendix, a series of non-geometric prose passages entitled Metaphysical Thoughts [Cogitata Metaphisica], Spinoza explicates Descartes' views on traditional metaphysical topics (including essence, existence, idea, potential, necessity, contingency, duration, and time) while furtively interpolating some of his own. Source: Wikipedia (en)