This chapter explores the value, complexity, and pitfalls of philosophy. The burden of this work is to show the value of Aristotle’s own argument that science—and human life—needs to be framed by philosophy. On this basis, we first consider how philosophy creates worldviews. We then consider ancient philosophy in more detail. We see that ancient philosophy is marked by the reduction of the world to a series of ideas, e.g. number, flux, atoms etc., which then widens to reduce the world, with Plato, to ideas, and then, with Aristotle, to beings. I show that Aristotle’s “realism” transcends the reductionism of his predecessors by grounding them and making them complex by showing how each ideology is one aspect or analogous dimension of a complex reality.