A short story by Roger Zelazny, set well after the end of human life. It explores the difference between man and machine. My copy is from the textbook Thought Probes

Humans created their robotic assistants, and set them to building up the world for them. After they had all died, the robots continued to develop the world. Man had placed Solcom in the sky, and the Alternate, Divcom, beneath the ground. Divcom was to be activated only if Solcom was unable to function. After a stray atomic missile (during the final annihilation of the humans) damaged Solcom, Divcom began to work. Solcom managed to repair itself, and the strife began. Neither would accept the other's rule of the world. This set up a system of good-versus-evil, though neither were "good" or "evil", more like two brothers arguing.

Two agents of Solcom were named Frost and Beta. Frost controlled the northern hemisphere, and Beta the southern. Frost was curious about humans, as he had never seen them. He began searching for what was left of the human civilization, and one day met Mordel. Mordel was a servent of Divcom, but brought Frost books written by the humans, and discussed what he knew.

Frost ends up making a deal with Mordel (and subsequently Divcom) that Divcom would provide resources for Frost to try to become human. If Frost failed, he would join Divcom forever (kinda like selling your soul). The rest is a journey of discovery about what makes a human human. (apologies for previously giving away the ending, to both those new and familiar with the story)

The title (and some decent quotes) come from A. E. Housman's poem A Shropshire Lad. Here is the bit from the story:

From far, from eve and morning and yon twelve-winded sky,
the stuff of life to knit me blew hither: here am I

...Now -- for a breath I tarry
nor yet disperse apart -- take my hand quick and tell me
what you have in your heart.
Thanks to tardibear for the link to the poem! The link was http:\\www.bartleby.com/123/32.html. Check it out for the rest. If someone (or I do) writes it up, I'll include that link here.