So you might not want to stand too close to the speaker of Sonnet 147 because the guy is feeling pretty under-the-weather these days.
"What's wrong?" you ask. Well, he's got a burning "fever" that's killing him and turning him into a raving madman. Metaphorically speaking, that is. You see, in reality, he's crazy in lust with someone he knows isn't good for him but, he just can't stay away from her because his desire is all sick and twisted like a "disease" (2).
We know that a lot of Shakespeare's 154 sonnets are about the pitfalls of sexual desire, but this is probably the scariest one of all. When literary critic Harold Bloom calls this "the most terrifying erotic poem [he] know[s]," we totally believe him (source).
Sonnet 147 falls toward the end of what literary critics like to call the "Dark Lady" sequence. That's the group of sonnets (127-152) that are mostly about the speaker's steamy affair with a dark-haired mistress. (Check out Sonnet 130 if you want to meet her because that's where the speaker gives us his infamous description of her physical features.)
So how do we know Sonnet 147 is about this "Dark Lady"? Well, to be fair, we can't ever really know for sure because the speaker never mentions any names and he doesn't really say whether or not he's talking about a man or a woman here. That said, we think there's a big clue in this sonnet's famous final couplet. That's where the speaker calls out his lover for being "as black as hell, as dark as night" (13-14). Translation: he's accusing someone of being ugly and morally corrupt. It turns out that bashing his mistress' dark physical features while accusing her of promiscuity is something the speaker does a lot in this sonnet sequence. What a jerk, right? (Head on over to "Calling Card," and we'll tell you more about it.)
A few more things before we turn you loose on this sonnet. We've said it before and we'll say it again: we know there are a ton of conspiracy theories out there about whether or not the sonnets are based on Shakespeare's life. (Heck. Even the guy who wrote A Clockwork Orange seemed to like the idea that Sonnet 147 is all about Shakespeare picking up a nasty case of syphilis (source)). These days, most scholars argue that there's no evidence that we can or should read the sonnets autobiographically. That's why we talk about the speaker of Sonnet 147 as if he's a character or—not Big Willy himself.
And finally, you should also know that Shakespeare probably cranked out his 154 sonnets in the 1590s but they weren't published together until 1609. That's when a shady guy named Thomas Thorpe published SHAKE-SPEARES SONNETS. Until then, it seems like Shakespeare probably just passed the sonnets around to close pals and a few patrons (a.k.a. the dudes who offered support and helped bankroll projects).
Look. We're not going to bother telling you that you should care about this sonnet because Shakespeare was the greatest poet who ever lived. That would be like "saying that King Kong is bigger than other monkeys." At least that's what Bard expert Stephen Booth is always saying (source).
What we will tell you is this: if your Sex-Ed teacher was going to use a poem as a scare tactic, Sonnet 147 would probably be the one you'd have to read in class… right before that horrifying slideshow that required a permission slip from your parents.
In other words, Sonnet 147 is all about the destructive power of uncontrolled sexual desire. It serves as a kind of cautionary tale about what can happen when lust gets out of control. Just look at our poor speaker—the guy knows he's in an unhealthy relationship with someone who is totally cheating on him but he can't stay away from her. (Even though there's some evidence in the poem that his mistress has given him a rather unpleasant STD, too.)