It's clear that the writer of this poem is a person who knows Lust before, during, and after its expression. He speaks about it “in action,” “till action,” and after action, when it is “despised straight.” Yet he offers up no personal experiences, and so seems distant in the advice he gives. Assumedly the shame he feels keeps him from going into detail. That he would feel the need to warn us, but simultaneously feel too much shame to relate his own, undoubtedly powerful story, says something about Lust; that it is truly grievous. This poem has a sort of do-as-I-say-and-not-as-I-did (please, for your own sake) tone, the sort that makes us want to know why Lust could make any man feel such a way, yet too distressed to find out more – either of his experience or by gaining our own – as his detached advice haunts the very thought. He so clearly tells us what Lust is like before, during, and after it takes us over, that we don't need to know what exactly happened to him in the end; his words hold just as much weight without that detail.
His last sentence is particularly powerful:
“All this the world well knows; yet none knows well
To shun the heaven that leads men to this hell.”
The semicolon’s placement makes us stop and pause. Who among of us doesn’t know that Lust is bad? All of us must, it’s one of the 7 cardinal sins. The writer acknowledges that we know this, but ends the line pointing out that we don’t know the full implications of lustful action.
In the second line, the writer acknowledges that acting lustfully can be heavenly, but it leads to “this hell.” Not just hell, but “this hell.” He sees himself as living in a sort of hell currently due to acting upon Lust. This draws our attention both to what it’s like to live after acting lustfully, and also to the consequences it bears in the afterlife: going to hell. Experiencing “heaven” on earth will lead you to hell in life and the afterlife. How much better the writer must think it to shun the desires of the body, perhaps enduring a different sort of hell (self-denial) for a different sort of heaven in life (peace of mind) and the afterlife: living without the regrets the writer has, and ultimate salvation.
Lust is a carnal desire that is associated with all kinds of distasteful human behavior when left unchecked. Not only is Lust “perjured, murderous, bloody, full of blame, savage, extreme, rude, cruel, not to trust” to those in contact with the person possessed by it, but also to the person whose decisions have made himself its marionette. It leeches onto those who let it take hold. We want to pity the lustful individual – Lust is described as so powerful it’s amazing anyone could resist – but the writer wouldn’t want that. He sees the succumbing of a person to Lust as a “waste,” a reason to “hate” the self for going “mad” from it, yet he doesn’t choose any words or phrases that encourages our pity on the lustful, including himself. By what the writer has chosen not to include, we can appreciate that the poem serves to warn us, not to elicit compassion or tell a story. He focuses on the fact that Lust has hated consequences, and he wants to save others from his fate, yet how we ultimately act is our decision. Reaping the negative things we've sown is nothing others should feel sympathy over.