"Courage Never To Submit Or Yield"
Context: These words appear as part of the first speech that Satan makes after being flung from Heaven and thrust into Hell. He looks about him at the rebel angels overwhelmed in the fires and recognizes Beelzebub beside him. Satan's words, directed to Beelzebub, comment on the changed state and appearance of the rebel angels and then reveal that Satan himself does not repent of trying to seize power in Heaven. Satan believes God is a tyrant and thus can rightfully be opposed and says that he intends, despite his defeat, to continue as God's adversary. He asks a rhetorical question and supplies its answer:
What though the field be lost?All is not lost; the unconquerable will,And study of revenge, immortal hate,And courage never to submit or yield:And what is else not to be overcome?That glory never shall his wrath or mightExtort from me.