Kant’s third question (“What may I hope?”) is underdiscussed in comparison to the other two, even though he himself took it to be the question that united his efforts in theoretical and practical philosophy. This is largely his own fault: in his discussion of the question he moves quickly from talking about rational hope to discussing the kind of Belief or faith (Glaube) that grounds it. Moreover, the canonical statements of his own moral proof do not seem to give hope any essential role to play. In this chapter I first consider the ways in which pre-Kantian authors muddied the distinction between what we would call “hope” and “expectation.” I then look at how Kant’s views about hope evolve to the point where, by the time of the “End of All Things” essay of 1794, he seems to endorse a kind of hopeful pessimism about our this-worldly situation, at least. I then examine a version of Kant’s moral proof that succeeds in locating a role for hope that is distinct from that of Belief, expectation, optimism, and so on. Finally, I turn to some contemporary work in two very different arenas – Anthropocene scholarship and Christian eschatology – in order to look at how the concepts of hope and optimism are deployed in those contexts. We will see that although some of the recent discourses about the “Good Anthropocene” slip beyond hope into full-blown optimism, most authors working on ecological and environmental topics are careful to keep the attitudes distinct. By contrast, there is a tendency among contemporary theologians to follow earlier Christian authors in slipping beyond mere hope to optimistic faith, and even to full-blown certainty.