Quatrain 2 Summary

Line 5

Nativity, once in the main of light,

• Line 5 begins the second quatrain of Shakespeare's sonnet. 
• He starts off the line by referring to "Nativity." As in, the scene of Christ's birth? Well, not quite. In fact, Shakespeare is actually using the literal meaning of this fairly abstract, religious term. He's just talking about a baby. 
• So, why didn't he just put it that way? We think he probably chose the more abstract word as a way of generalizing—of saying, "You know what? What I'm talking about here literally happens to everybody."
• Fine. So what's this universal baby of sorts doing? Actually, we don't know. All we know is where the baby is—in a "main of light." Or, we sort of know—because the way Shakespeare talks about it is actually kind of weird.
• What's a main of light? The main problem here (ba-dum ching!) is the meaning of the word "main." Here, it's being used in an old-fashioned sense. According to this meaning, main means the sea. You may have heard this meaning before in movies about pirates, where they talk about the "Spanish main."
• This clears things up a bit, but not completely, since it's pretty clear that "main of light" is something of a metaphor. What Shakespeare is most obviously getting at is the idea of a really big amount of light—a sea of light, to be precise.
• But wait. There's more. As critic Stephen Booth points out, the phrase "main of light" also has an effect on the way we read the word "Nativity" at the beginning of the line. That's because the ocean imagery makes us think of that birth as the (metaphorical) birth of the sun as it rises out of the waters of the horizon. Beautiful, right? It really looks like a "main of light." 
• Keep this idea of the sun in mind as we continue on to the remaining lines in Quatrain 2, where this metaphor becomes a full-fledged conceit. As you can see, most of them can also be interpreted as metaphors based on the sun's progress through the sky.

Line 6

Crawls to maturity, wherewith being crowned,

• But enough blabbing about Line 5. Let's see what Mr. Fancy-Pants "Nativity" actually does.
• Well, the first thing he does is grow up—this is what Shakespeare means by the highly metaphorical phrase "[Nativity] crawls to maturity." 
• In a way, you can think about the imagery in this line as being like one of those old "ascent of man" illustrations. Except, of course, that Shakespeare's diagram would begin with a baby, not an ape… and it wouldn't end with a spaceman… you get the idea.
• Okay, so far we've only dealt with the first three words of the line. What about the rest? First on the agenda: "wherewith." What the heck does "wherewith" mean?
• Nothing too fancy, actually. "Wherewith" just means with which—referring to maturity, of course. So the line as a whole basically means, "[Nativity] crawls to maturity, with which, being crowned…" or, if you want to simplify it even further, "[Nativity] crawls to maturity; and, when it is crowned with that…" and so on. Notice that neither of these is a complete sentence, which means the line is enjambed. To figure out everything that happens, we're going to have to wait until the next line(s). 
• There are some other ideas in play here, too. For one thing, it seems like this speaker is sure that maturity is a good thing—as you can tell from the use of the word "crowned." That means that Line 6 is describing the process to adulthood as one to bigger and better things. 
• Because of the hints of sun imagery in Line 5, it makes sense to think of Line 6 as continuing this imagery. So try imagining the process of "crawling to maturity" as paralleling how the sun climbs up to the highest point of the sky—its point at noon. 
• Does talking about this imagery give you any sense of where the poem might be going next? Think about it: when you're at the top, what's the only direction you can go? 

Line 7

Crookèd eclipses 'gainst his glory fight,

• If you answered down to the question we asked at the end of our discussion of Line 6, you are correct, sir! Or ma'am.
• Line 7 matches up with the sun imagery we've been tracking throughout the second quatrain. When the sun reaches its highest point in the sky—its point at noon—it has nowhere else to go other than down the other side of the sky. When the sun eventually sets in the west, this brings on night. 
• But wait—this isn't the route Shakespeare takes with his sun imagery at all. That rising-in-morning, declining-in-evening stuff is just too simple for Big Willy.
• Instead, he has to go and really lay it on thick. The sun in this poem doesn't just set, it gets eclipsed. And not just by one eclipse, but by eclipses. And not just by eclipses, but by crooked eclipses—i.e., especially distorted and bad ones. Yikes. This sun is not in good shape.
• What could possibly be next? Let's turn to Line 8 to find out.

Line 8

And time that gave doth now his gift confound.

• It's hard to get a more final statement of time's destructive power than this line. Just listen to the completely regular, thumping, ominous beat of the iambic pentameter here: And time that gave doth now his gift confound. Like a heart beating furiously away, the rhythm alone gives you a powerful sense of the destructive power of time—even before you know what all the words mean. 
• As for those words? The only real tricky one, we think, is "confound." The meaning of the word in this context is pretty simple: according to critic Steven Booth, it means "'destroy,' 'demolish,' and, in military contexts, 'defeat'" (source).
• This line might also be a sneaky allusion to the Book of Job in the Bible, which says, "Naked came I out of my mother's womb, and naked shall I return thither: the Lord gave, and the Lord hath taken away; blessed be the name of the Lord."
• The basic idea of this line (and of this entire second quatrain) is that time, who started out as the good guy—the one who enabled Line 5's "Nativity" to be "crowned" with "maturity" in Line 6—turns out to be the bad guy. Time destroys what he makes. 
• Any guesses about who's going to take center stage in quatrain 3?