Stanza 3 Summary

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

We sat grown quiet at the name of love;
We saw the last embers of daylight die,

The mention of "love" seems to have shut them up. We wonder why. Perhaps each of them has their own heartache to consider.
As they sit and think, the sun finally goes down. Yeats uses a simile here to compare the sunset to the "last embers" of a fire burning out.
Notice the change in tone at this point? Yeats uses words like "last" and "die" to turn the poem from its milder, peaceful tone to one that gets a little more serious, a little heavier.

And in the trembling blue-green of the sky
A moon, worn as if it had been a shell

The speaker describes the sky as "trembling blue-green." It sounds pretty, but how can a sky tremble?
Perhaps a bit of personification is to blame, as the speaker gives a color combination the ability to feel nervous.
Remember how the mention of love made all three of the characters in the poem go silent? They seem to be feeling a little shaky as they consider the state of their love lives.
Ever notice how, when you are sad and heartbroken, even neutral things like the moon seem to be sad, too?
That's what's at work here. The speaker's sadness carries over into the way he sees the moon.
Here's another simile: the moon is compared to a shell, worn by the waves of the sea. That would make it nice and smooth, right?

Washed by time's waters as they rose and fell
About the stars and broke in days and years.

The speaker continues this moon imagery in these next lines. Instead of the sea washing over the shells to make them smooth, though, it's time that has washed over the moon to smooth it out.
The mention of love made our speaker consider time, and how it passes. The moon imagery is a way to make us consider the physical marks of time.
Notice the sound play ("washed" and "waters") going on here? Check out the "Sound Check" for more on Yeats' sonic tricks.

I had a thought for no one's but your ears:
That you were beautiful, and that I strove
To love you in the old high way of love;

Ah, so this is why he got so quiet when they mentioned love. Our speaker's in love with the woman to whom he is addressing this very poem. How does that revelation change your reading?
He's thinking about how beautiful she is as she sits right next to him. Gee, we hope her friend doesn't feel too awkward.
The speaker wants to love her the old-fashioned way that lovers used to, by studying books and learning quotes about love.
He calls this way the "high" way because he considers it to be classier than the way lovers are in his time (wonder what he'd think about wooing someone via text message).

That it had all seemed happy, and yet we'd grown
As weary-hearted as that hollow moon.

We guess time hasn't been too kind to these two lovers. It had seemed happy at the beginning, but now, they're "weary-hearted."
Our speaker uses the moon as a metaphor for how time changes our hearts, making them too tired to be chivalrous.
Is the moon also a metaphor here for the art of love and poetry, which have also grown old?
Maybe—after all, the poem keeps reminding us that nobody thinks poetry or love are worthwhile endeavors anymore. Sad.