I’m quoting from memory, so forgive me if I miss the phrasing, but the gist of it is, to my recollection:
“Some say the world will end in fire,
Some say ice.”
So far, the poem is straightforward enough. Everybody has questioned at one time or another their fate.
“From what I’ve tasted of Desire,
I side with those who favor Fire”
The word “Desire” is a literary innuendo for passion. As such, Frost is saying that as someone who has tasted passion, he prefers the idea of meeting his end at the hands of Fire ( another passion innuendo), rather than to ice (stagnancy).
“But if the world had to perish Twice,
I think I know enough of hate,
To say that for Destruction,
Ice is great and would suffice”
Now this is the true power ballad of the poem. Just as he portrayed the end of passion as a fiery death, he alludes to Ice being the catalyst of hate. Therefore, the stagnancy of Ice is being portrayed as an evil to the point of it being the incarnate of Hate. Finally, Frost ends this prose my stating that in the end, it doesn’t really matter, and if Destruction is the “end” then both Fire and Ice are justifiable.
The poem, “Fire and Ice” is a treatise on a number of philosophies. It conveys the theme of “Carpe Diem” in it’s reference to the fact that the end of days is unknown to all, and those whom spend their time worrying to what ends they will fall inevitably lose the ability to reside in the moment. Frost prefers the idea of going out in a blaze of glory to the idea of dying cold, dispassionate, and stagnant.