We think "sinews of the heart" is pretty sexy, and there are definitely some beating hearts in this poem (check out line 11). Mr. Blake certainly knows how to get our attention with words like "furnace" (14) and lines like "when the stars threw down their spears" (17). To be sure, nobody’s getting it on in this poem, but the speaker’s passionate nature is highly contagious. Don’t believe us? Read the poem aloud, and then check your pulse. We bet your heart will be racing.