A man may be a cheerful pessimist or a melancholy optimist.
 Bertrand Russell, A History of Western Philosophy (1945). copy citation

Context

“Uncomplicated joy and sorrow is not matter for philosophy, but rather for the simpler kinds of poetry and music. Only joy and sorrow accompanied by reflection on the universe generate metaphysical theories. A man may be a cheerful pessimist or a melancholy optimist. Perhaps Samuel Butler may serve as an example of the first; Plotinus is an admirable example of the second. In an age such as that in which he lived, unhappiness is immediate and pressing, whereas happiness, if attainable at all, must be sought by reflection upon things that are remote from the impressions of sense.” source