 The influence of Arabic ethical and political writings is thin, partly because Arabic philosophers were less productive in these fields, and partly because important works were not translated at all (such as al-Fārābī’s Principles of the Citizens of the Perfect State) or as late as in the sixteenth century (such as Averroes’ Commentary on Plato’s Republic). Nevertheless, Arabic philosophers, via their teaching on the intellect, exerted an important influence on the border area between ethics and psychology, and on the discussion of human happiness in particular.