The life of contemplation

In Book 10 of the Nicomachean Ethics, Aristotle argues that the best (happiest) life for human beings is the life of contemplation. State Aristotle’s argument for this claim, and assess its consequences for the relative value of the political life (that is, the life of moral virtue). In particular, does Aristotle’s elevation of the contemplative life problematically undermine the value of the political life? Defend your answer.