A propensity to hope and joy is real riches one to fear and sorrow real poverty.

The sentiment contrasts inner dispositions with external wealth: to be naturally inclined toward hope and joy is to possess a durable “riches” that cannot easily be taken away, while a habitual tendency toward fear and sorrow amounts to “poverty,” even if one has material abundance. Read in a broadly Humean key, it treats happiness as grounded in temperament, passions, and habits of mind rather than in possessions. The line also implies an ethical counsel: cultivate hopeful, cheerful affections and resist anxious, melancholy ones, because the quality of one’s experience—and thus one’s practical “wealth”—depends largely on these recurring emotional orientations.