 The philosophical thread that runs through Galileo’s intellectual life is a strong and increasing desire to find a new conception of what constitutes natural philosophy and how natural philosophy ought to be pursued. Galileo signaled this goal clearly when he left Padua in 1610 to return to Florence and the court of the Medici. He asked for and received the designation ‘Philosopher’, in addition to ‘Mathematician’. This was not just a status-affirming request, but also a reflection of his programmatic aims. What Galileo accomplished by the end of his life was a reasonably articulated replacement for the traditional set of analytical concepts connected with the Aristotelian tradition of natural philosophy. He offered, in place of the Aristotelian categories, a set of mechanical archetypes that were accepted by most everyone who afterwards developed the “new sciences,” and which, in some form or another, became the hallmark of the new philosophy. His way of thinking became the way of the Scientific Revolution (and yes, there was such a revolution, pace Shapin 1996 and others; see the selections in Lindberg and Westman 1990; Osler 2000).