Stanza 1 Summary

Get out the microscope, because we’re going through this poem line-by-line.

SOUL
O who shall, from this dungeon, raise
A soul enslav'd so many ways?

The soul gets the first word, and it wastes no time getting its complaint out there. It's trapped and it wants out. Using a metaphor to call its body a "dungeon," the soul complains that it's "enslav'd." Sounds like bad times.
Even though this poem's called a "dialogue," you'll notice that the soul isn't addressing the body directly. Formed as a rhetorical question, these lines are a plea for help but with no real expectation that help is on the way. The soul doesn't say, "Hey, get me out of here!" Instead, it takes the damsel-in-distress line, wondering aloud, "Who, O who will come to my aid?"
Feeling stressed? It's not just the soul's dire mood—this whole poem's got stress, iambic tetrameter, to be exact. Get yourself down to "Form and Meter" for the skinny.

With bolts of bones, that fetter'd stands
In feet, and manacled in hands;

Back in line 2, the soul was carping about the "many ways" it's enslaved, and now we get the first descriptions. For starters, the body's bones are called "bolts," a metaphor that makes the skeleton seem like a prison.
The jailbird theme continues with some head-scratching paradoxes: the soul is "fetter'd" (or restricted) by having feet and "manacled" (in manacles, or handcuffs) by having hands. Most people would be like, "Yes, I have feet and they let me walk down the street to my favorite cafe," but the soul is not interested in picking stuff up or dancing. It just wants to be a soul, okay, and do soul things. Any body part, however useful, is just part of the dungeon.
Check out the double-whammy of alliteration (the B sounds) and assonance (the long O sounds) in "bolts of bones." This soul knows how to hammer it home. Keep an eye peeled for more examples throughout the poem and, for the down and dirty on soul-and-body-style, head to "Sound Check."

Here blinded with an eye, and there
Deaf with the drumming of an ear;

Whip out those binoculars, 'cause it's paradox-spotting time. After hitting us with handcuffs and chains in lines 3-4, the soul gets two more in, claiming that it's blind because it has eyes and deaf because it has ears. Huh?
If this sounds kinda counterintuitive, don't worry—it's supposed to be. The soul is trying to startle us out of our bodily assumptions, like thinking that eyes help us see and ears help us hear. The point is to change our perspective so we see the soul's side of things. Because it doesn't need ears or eyes to function, they're just nuisances—in fact, for the soul they do exactly the opposite of what they do for the body.
Did someone say pun? "Drumming" here refers in general to all the sounds taken in by the ear, but it's also a pun on "eardrum." Get it? Boy, that Marvell: what a barrel of laughs.
Before you leave, admire the eye rhyme of "deaf" and "ear," which gives a cute balance to the line.

A soul hung up, as 'twere, in chains
Of nerves, and arteries, and veins;

Let me count the ways… The soul's still nattering on about its slavery and let's face it: the imagery is pretty intense. We've had prison; now we're moving on to torture, with the soul describing itself as strung up in chains, the way a prisoner might have been treated in seventeenth-century jail.
But spoiler alert: these chains aren't actually long links of iron. Line 7 ends creepily on "chains," but the "as 'twere" embedded in the middle has already given the heads up that we're drifting into simile territory.
Bam! Line 8 brings it back to the body. The soul is strung up in the body's natural chains, all those ropy things that pump blood and pass signals from your brain. For the body, these guys are life-essential; for the crotchety soul, however, they're instruments of torture. Eesh.

Tortur'd, besides each other part,
In a vain head, and double heart.

Line 9 comes right out and says it: this crap constitutes torture. In addition to the bones that restrict movement, the eyes and ears that dull the soul's senses, and the body's tormenting communication networks, the soul has to deal with vanity and duplicity. The "vain head" suggests (by using a rare, but cool, technique known as synecdoche) that the brain's intelligence is shallow and arrogant, while the "double heart" is a metaphor that hints at emotional deception and disloyalty.
Up till now the soul's been on a physical body rant, complaining about bones and ears and nerves. This is the first sign that the soul's on the outs with the mind as well. We're moving from physical to metaphysical, folks.
But wait a gosh-darned second! What is a soul anyway, if it's not the mind or the heart-conscience? Is our soul losing its marbles here? Did it forget who it is? Figuring out what the seventeenth-century soul is can be a trying business. Head back up to "In a Nutshell" for more info on just what = soul and what = body.