Philosophy begins in wonder, according to Plato and Aristotle. So what contribution does wonder make to a philosophical life? As a passion of inquiry, wonder is both a part of the intellectual pursuit of philosophy (a passion of inquiry), and a part of the ethical life of the philosopher (a passion of inquiry). The Hellenistic schools of philosophy problematized the relation between the intellectual and the ethical roles of wonder. In this dissertation, I map out the valences of wonder in the Aristotelian corpus, Stoicism, Epicureanism, and Pyrrhonian Skepticism. In the first chapter, I briefly discuss Plato’s statement that philosophy begins in wonder (from the Theaetetus) in the context of Diotima’s account of philosophy in the Symposium. Then I give a reconstruction of Aristotle’s account of the role of wonder in philosophy, both by analyzing the theory of wonder as presented in Metaphysics A2, and by looking at how he mobilizes wonder in actual inquiries. The second chapter deals with Stoicism. Our sources suggest that wonder was important in Stoicism in two different domains. In theology, both Cicero (De natura deorum book 2) and Sextus Empiricus present Stoic arguments for the existence of the gods that rely on wonder. In ethics, wonder is a problem for Stoics, as wonder at the wrong objects can lead to greater emotional turmoil. I describe the basic outline of this ethical challenge by a reading of Epictetus, and then turn to Seneca for a more robust account that accommodates both the appropriate theological wonder and the caution against ethical wonder. I turn to Epicureanism in the third chapter. It appears from a passage from the Letter to Herodotus that Epicurus held that the wonder caused by inquiries into nature can be a reason to limit our curiosity for the sake of happiness. In particular, Epicurus is worried that wonder at natural phenomena can easily lead to fear of the gods. Lucretius shares this concern, and makes a point of dispelling particular marvels. As I demonstrate, Lucretius has a number of strategies to achieve this. Moreover, I argue that Lucretius mobilizes wonder through poetic effects to bolster his didactic aim: instilling wonder in the reader to debunk it right away. The fourth chapter, on Pyrrhonian Skepticism, is based on evidence from Sextus Empiricus and Diogenes Laërtius. As far as we can tell, wonder shows up in two different but related places in the Pyrrhonist framework: it is one of the targets of the ninth mode of suspension, as well as one of the modes of persuasion. In both instances, wonder figures more as an obstacle to ἀταραξία than as a positive factor in inquiry. Because wonder is located on the interface of inquiry and ethics, a philosophical school’s attitude towards wonder is a valuable indicator of its metaphilosophy, or its vision of what philosophy is for and what a philosophical life demands of us.