Abdiel is welcomed back into heaven and praised for his courage. God then sends Michael and Gabriel with his army to defeat Satan’s army.
The battle ensues with a tremendous din. Soon, Satan and Michael find themselves face to face. They duel by sword. Michael swings his sword, cuts through Satan’s own, and cuts Satan’s right side. Satan feels pain for the first time.
Satan’s angels run to defend him and carry him back to his chariot. Satan soon heals, but his pride is hurt. He is supposed to be equal to God and but here he gets knocked down by a simple archangel.
Satan and his forces find themselves beaten back for the time being. Night falls in heaven and Satan retreats and calls a war council. There, he turns the defeat into victory. If God was infallible, he says, why were the fallen angels able to survive a whole day and then allowed to retreat. Why weren’t they entirely squashed? If they could battle God for “…one day, why not eternal days?”
Satan suggest they return to battle the next day with more powerful weapons that they could construct using heaven’s natural resources, i.e. gunpowder and cannons.
The next day, Satan’s forces surprise God’s army by using the cannons, and thousands of good angels are knocked down. But the good angels soon run to the surrounding nature of heaven and start throwing the actual hills back at Satan’s army. All of heaven is engulfed in confusion: the hills are being uprooted on both sides and thrown across the battlefield.
On the third day of battle, God sends in his Son. The Son tells God’s army to relax and he rides forward in his spectacular chariot to face Satan’s army alone. As he rides, the hills assume their natural positions and heaven starts to look normal again.
The Son charges after them with lightning bolts. Satan’s army turns and runs away in horror. A breach opens in the wall of heaven and the whole of Satan’s army falls through and cascades down to hell.
Milton is making a political critique with his rather strange allusion to cannons and gunpowder. A new invention at the time of his writing, many of Milton’s contemporaries actually did view the use of cannon and gunpowder as a weapon inspired by the devil. Perhaps analogous to nuclear warfare in our own time, the use of artillery was revolutionizing the way wars were won. They increased the efficiency of war, that is, they increased the amount of casualties possible in a small span of time. At the same time, they made war more impersonal. One no longer had to see the enemy to kill them. Because of this, society had to change, or completely lose, its concepts of the hero and of chivalry. In a sense, the use of artillery was somehow cheating, somehow taking away from the honor of war, and therefore originated from a less than honorable source.
Milton actually gives a rather poetic technical description of how the cannon works. The “other bore” is the touch-hole or cavity of the barrel. The “touch of fire” is where the cannon is lit, actually called a touch-powder.
There are no coincidences in Milton, every number, every reference to a star, nearly every word is a clue or key to another meaning. On a very superficial level we can see this in Milton’s numerology. The third day of battle, of course, corresponds to the three days Jesus Christ was in the tomb in the Christian New Testament. Christians believe that when Christ was resurrected on the third day, raised from the dead, he defeated death. Death, we will remember, is Satan’s son. So when the Son goes out on the third day to battle Satan and his army, Satan’s defeat is a direct correlation with Jesus Christ’s victory over death. It is notable that the Son battles the whole of Satan’s army without any help from the God’s angels. Likewise, Jesus Christ’s crucifixion and death was faced without any help from angels.
The torn up hills of heaven are also put back in their place and nature resumes its order when the Son passes by on his chariot. Again, in a macrocosmic sense, the Son is ordering, making rational once again, what was chaos by his mere presence. So he will make mankind ordered, rational, and good when he comes the earth in the form of Jesus the Christ. In lines 723 -33, in fact, the Son is reciting exact phrases from Jesus’ last supper.
Another Biblical allusion at this point is the simile of 856-857 comparing Satan’s retreating army to a flock of sheep which will ultimately be driven off a cliff and fall. The story of the Jesus casting the devil into the Gaverene swine from the Gospel of Mark and then the swine running off a cliff is implied.
Turning to the poetic elements once again, it is interesting to note Milton’s repeated use of certain words. “Fruit,” “fall,” “forbidden” are, of course, used quite often and not always in the most obvious contexts. Interestingly, Milton avoids using the word “original,” though theologians continually use the word to refer to the fall of Adam and Eve. And the word “all” is used a tremedous number of times, 612 times to be exact, at the rate of about once every seventeen lines. This use of this word shows the absolutist nature of Milton’s concept of purity and corruption. They are extremes in Milton’s mind, and the possibility of all-goodness or all-evil is wholly possible in his universe.