''Caligula'' reveals some aspects of the existential notion of the absurd' by portraying an emperor so mighty and so desperate in his search for freedom that he inevitably destroys gods, men and himself. The dramatic impetus of ''Cross Purpose'', however, comes from the tension between consent to and refusal of man's absurdity; it is the tragedy of a man who returns home to his mother and sister without revealing his identity to them. By the time of ''The Just'' and ''The Possessed'', refusal and rebellion have taken over, and in these overtly political plays (the latter based on Dostoyevsky's ''The Devils'') Camus dramatizes action and revolt in the name of liberty.