This is a book about what the historian of philosophy does when reading. It is a book, therefore, that attempts to catalogue the various types of thinking produced in and through the act of reading a philosophical tex). Since Descartes, the philosopher has been persistently imagined as someone who thinks rather than reads, as someone who throws away the books handed down by tradition in order to properly begin meditating. And this binary has determined the image of the historian of philosophy too: the very practice of rational reconstruction informing so much contemporary history of philosophy is one which attempts to 'draw the curtains of words' to access what Danto called the 'pure units of philosophy' lying behind the text. Beginning from a series of problems set by Martial Gueroult, this book contests both the mutually exclusive binary of thinking and reading and the image of the historian of philosophy it gives rise to. And it does so by giving an account of history of philosophy as a readerly