If a man spends his time struggling to survive, he cannot philosophize. Philosophy is dependent for its existence on the community of men. The philosopher distinguishes between knowledge and opinion. He does not recognize any authority but reason. He seeks to replace opinion with knowledge.
Men have opinions about the good and the bad, the just and the unjust.
The philosopher questions these opinions in an effort to know the truth about them. It may be said that the philosopher is in the business of destroying opinion. Ignorance remains, but not without knowledge. Everywhere that men live, there are opinions about the highest things. Every regime that is or has ever been has had its opinions about the highest things.