Perhaps the most famous proposition in the history of philosophy is Descartes' cogito 'I think, therefore I am'. Husain Sarkar claims in this provocative interpretation of Descartes that the ancient tradition of reading the cogito as an argument is mistaken. It should, he says, be read as an intuition. Through this interpretative lens, the author reconsiders key Cartesian topics: the ideal inquirer, the role of clear and distinct ideas, the relation of these to the will, memory, the nature of intuition and deduction, the nature, content and elusiveness of 'I', and the tenability of the doctrine of the creation of eternal truths. Finally, the book demonstrates how Descartes' attempt to prove the existence of God is foiled by a new Cartesian Circle.