Milton shows his own attitude toward Satan in the way the character degenerates or is degraded in the progression of the poem. Satan is magnificent, even admirable in Books I and II. By book IV, he is changed. In his soliloquy that starts Book IV, Satan declares that Hell is wherever he himself is. Away form his followers and allowed some introspection, Satan already reveals a more conflicted character.
Similarly, Satan's motives change as the story advances. At first, Satan wishes to continue the fight for freedom from God. Later his motive for continuing the fight becomes glory and renown. Next, the temptation of Adam and Eve is simply a way to disrupt God's plans. And, at the end, Satan seems to say that he has acted as he has to impress the other demons in Hell. This regression of motives shows quite a fall.
Satan also regresses or degenerates physically. Satan shifts shapes throughout the poem. These changes visually represent the degeneration of his character. First, he takes the form of a lesser angel, a cherub, when he speaks to Uriel. Next, he is a ravening cormorant in the tree of life — an animal but able to fly. Then he is a lion and a tiger — earth-bound beasts of prey, but magnificent. Finally, he is a toad and a snake. He becomes reptilian and disgusting. These shape changes graphically reveal how Satan's actions change him.
Even in his own shape, Satan degenerates. When Gabriel confronts Satan in Book V, none of the angels initially recognize Satan because his appearance is noticeably changed. Likewise, in Book X, when Satan once again sits on his throne in Hell, none of the earlier magnificence of his physical appearance is left. Now he looks like a drunken debauchee.
