A Robin Red breast in a Cage
Puts all Heaven in a Rage. (5-6)
This is the first of Blake's animal couplets—and it sets the pattern for the rest. A small example of a bird suffering and losing its freedom really reflects all suffering and the death of all freedom. It's enough to tick heaven off.
A dog starv'd at his Master's Gate
Predicts the ruin of the State. (9-10)
Like the robin one, this couplet shows how a smaller example of cruelty can reflect greater sufferings. If the relationship between a dog and its master gets this bad, it probably means that the master isn't treating the humans who work for him very well either. The whole social order might fall into revolution—or pure tyranny.
He who the Ox to wrath has mov'd
Shall never be by Woman lov'd. (31-32)
This one might seem silly—but Blake's saying that, if you're in the habit of picking on innocent animals, you're probably not going to appear very lovable to humans either.
The wanton Boy that kills the Fly
Shall feel the Spider's Enmity (33-34)
This one's interesting. Blake is implying that there's some kind of karmic law at work in the universe—if you kill flies, you're going to find out what it's like to die as a fly. Even though there's suffering in the world, there's also justice.
The Babe that weeps the Rod beneath
Writes Revenge in realms of death. (73-74)
This couplet is about human suffering, specifically—unlike the other couplets, which mostly deal with animal suffering. Like the one about the boy killing flies, this couplet also implies that there's some kind of cosmic justice at work in the universe: the abused baby will be avenged.
The Harlot's cry from Street to Street
Shall weave Old England's winding Sheet.
The Winner's Shout, the Loser's Curse,
Dance before dead England's Hearse. (115-118)
This one is more about social injustice than specific individual examples. The plight of poor women who've been forced into prostitution and of losing gamblers will eventually help run England into the ground, and destroy the nation.
To see a World in a Grain of Sand
And a Heaven in a Wild Flower,
Hold Infinity in the palm of your hand
And Eternity in an hour. (1-4)
These lines provide the key to the rest of the poem. Blake wants you to take its advice, and look for big realities hidden in small images.
The wild deer, wand'ring here & there,
Keeps the Human Soul from Care. (21-22)
A carefree human soul is kind of like a wild deer—since the deer doesn't have any greater obligations, it's free to go where it wants to go. Unlike the robin in a cage at the beginning of the poem, the deer is an image of freedom.
Joy & Woe are woven fine,
A Clothing for the Soul divine;
Under every grief & pine
Runs a joy with silken twine. (59-62)
Joy and woe are like clothing for the soul because they're experiences that it puts on when it enters the world. Joy is made of "silken twine" because it's like the fine Under Armor that lies beneath a coarse layer of outerwear (woe).
To be in a Passion you Good may do,
But no Good if a Passion is in you. (111-112)
Blake doesn't want people to be driven by passion—he wants them to drive it, and to stay in control. You should use passion, but not be used by it.
Every Night & every Morn
Some to Misery are Born.
Every Morn & every Night
Some are Born to sweet Delight.
Some are Born to sweet Delight,
Some are born to Endless Night. (119-124)
People are passing through different states all the time in this world, says Blake. They could be headed from joy back to suffering, or through suffering back to joy. (He might be implying that joy will only be permanent in eternity.)
The Babe is more than swadling Bands;
Throughout all these Human Lands. (63-64)
In a coded way, Blake is saying that the soul is more than the physical body, just like a baby is more than the swaddling bands that wrap around him/her.
He who mocks the Infant's Faith
Shall be mock'd in Age & Death.
He who shall teach the Child to Doubt
The rotting Grave shall ne'er get out.
He who respects the Infant's faith
Triumphs over Hell & Death. (85-90)
Since Blake sees faith as being a basic part of human beings, destroying faith makes people less human, whereas supporting it helps make them more human.
We are led to Believe a Lie
When we see not Thro' the Eye
Which was Born in a Night to Perish in a Night
When the Soul Slept in Beams of Light. (125-129)
The material world is like a nightmare that the soul is having—it deludes itself into believing the nightmare is real by trusting too much in its physical senses. Blake wants people to try to reach beyond those five senses.
God Appears & God is Light
To those poor Souls who dwell in the Night,
But does a Human Form Display
To those who Dwell in Realms of day. (129-132)
In the material world, God doesn't really appear, except in a distorted form as the light that comes from the sun and makes things visible. But, in heaven or eternity (the "realms of day"), God appears as a living human reality.
A Skylark wounded in the wing
A Cherubim does cease to sing. (15-16)
When a bird gets wounded, an angel gets hurt too—that's what Blake is saying. Since "all that lives is holy" (in the words of Blake's "The Marriage of Heaven and Hell"), a bird is as important in God's eyes as a human or an angel.
The Caterpillar on the leaf
Repeats to thee thy Mother's grief. (37-38)
This is a complicated one—apparently, the caterpillar reminds people of Eve, the "Mother" of humanity, whose sin in eating the forbidden fruit led humanity to fall from Eden. For Blake, the fall from Eden caused the creation of the natural world (which is really an illusion) and the descent of the spirit into lower life forms (like caterpillars, which feed off the natural world).
Man was made for Joy & Woe;
And when this we rightly know
Thro' the World we safely go. (56-58)
If you're not expecting everything to be sunshine and roses, you'll have a better time—you'll be prepared for suffering and won't have a lot of faulty expectations.
Every Tear from Every Eye
Becomes a Babe in Eternity.
This is caught by Females bright
And return'd to its own delight. (67-70)
This is another complex mini-poem in itself, but basically it's saying that suffering is eventually redeemed. Sorrow will give birth to delight, at some point.
The Bleat, the Bark, Bellow & Roar
Are Waves that Beat on Heaven's Shore. (71-72)
This might mean that the cries of suffering and anger experienced on earth lead to some sort of reaction in heaven—probably redemption.
The Strongest Poison ever known
Came from Caesar's Laurel Crown. (97-98)
Blake is restating the old principle that absolute power corrupts absolutely, and the desire for power is particularly poisonous.
The Bat that flits at close of eve
Has left the brain that won't believe.
The Owl that calls upon the Night
Speaks the Unbeliever's fright. (25-26)
Blake uses a bat and an owl as symbols for the minds and thoughts of unbelievers because they're nocturnal creatures. They're stuck in the darkness of the material world and don't have access to the light of the spirit or of imagination.
A truth that's told with bad intent
Beats all the Lies you can invent. (53-54)
It's worse to use a truth for false purposes than it is to just tell a lie. Not only does it cause harm, it corrupts the truth in the process. On the other hand, you might tell a lie for a basically positive reason.
He who replies to words of Doubt
Doth put the Light of Knowledge out. (95-96)
For Blake, there's no point in arguing with someone who's a professional doubter, since they don't really want to be convinced. You'll just end up doubting your own convictions if you fall into this kind of argument.
A riddle or the cricket's cry
Is to doubt a fit reply. (103-104)
Blake suggests that, instead of getting into an unproductive argument with someone who's not interested in being convinced, you might as well drop a riddle on your interrogator.
The emmet's inch and eagle's mile
Make lame philosophy to smile. (105-106)
Since the emmet (or ant) is close to the ground and the eagle's far above it, Blake's saying that discussing the limits of perception is something that's making philosophy feel a little overconfident. (After all, philosophy itself can't lead to new perceptions, but can only reason about preexisting ones—that's why it's "lame.")
If the Sun & Moon should doubt
They'd immediately Go out. (109-110)
The sun and moon are too busy doing their thing—radiating and, in the moon's case, reflecting light—to be distracted by a lot of trivial doubts that don't lead anywhere. Maybe, implies Blake, humans should be doing the same?