Hope obeys Aristotle's doctrine of the mean: one should neither hope too much, nor too little. But what determines what constitutes too much and what constitutes too little for a particular person at a particular time? The sceptic presents an argument to the effect that it is never rational to hope. An attempt to answer the sceptic leads us in different directions. Decision-theoretic and preference-theoretic arguments support the instrumental value of hope. An investigation into the nature of hope permits us (...) to assess the intrinsic value of hope. However, it must be granted to the sceptic that there is a tension between hope and epistemic rationality. I conclude with some reflections about the relationship between hope and character features that are constitutive of inner strength. (shrink)