This Chapter concludes the argument and has two segments: First, a "Coda" rounds out and underlines the key themes of this study, with special emphasis on what Descartes himself could have understood as the "mathematical" bent of his natural philosophical enterprise, given what we have discovered in this volume. Then, an "Epilogue" surveys some salient points about the subsequent career of the mature Descartes, illuminated by our study of his earlier career. In addition, we discover his (somewhat surprising) relations to the next phase in the Scientific Revolution, and hypothesize about what might have happened, had he lived into that phase (whose contours were analyzed as part of the conceptual and historiographical foundations set down in Chap. 2).