Significance of Raskolnikov's dream in Crime and Punishment?

[Trooper]

There is a point in the story (early, before the murder) where Raskolnikov faints out of exhaustion and has a dream. He dreams of an event where a band of drunkards torture and finally kill a horse tied to a wagon. What are your thoughts on the meaning of this? Did the event actually happen, or did Dostoyevksy have another interpretation in mind?

[armenian]

i believe it to be a event in rask's when he was a little boy that left an impression on him. the boy feels compassion is helpless to help the horse (the victim) like rask's own guilt over killing the old woman is getting to him.

its also similar to the time when rask' noticed and tried to protect the young drunk girl.

[Gladys]

[Raskolnikov] dreams of an event where a band of drunkards torture and finally kill a horse tied to a wagon.

It's also similar to the time when Rask' noticed and tried to protect the young drunk girl.
By the end of the book, I had forgotten about this dream and the incident with the young drunk girl where, as the policeman leaves to safeguard the girl from Svidrigaïlov, Raskolnikov calls to him, "Let them be! What is it to do with you? Let her go! Let him amuse himself."

I understand both incidents as reflections of the nihilism of Raskolnikov. He reacts to life without morals or meaning, and to the way in which some, like Napoleon, choose there own brutal, but glorious, pathway. Except for guilt (at least, in relation to Lizaveta) and overwhelming compassion (albeit intermittent), Raskolnikov shares something of the anarchic worldview of Mersault in Camus' L'Étranger.

I am unclear why exactly Raskolnikov fails to emulate the free-thinking arrogance of a Napoleon. He seems to be undermined even as he murders. His sister Dounia, his mother, Sonia and Razumikhin hardly contribute to his impotence. Something internal is limiting Raskolnikov. But what?

[bazarov]

I could swear I saw that dream in some other Fyodor's novel! But I can't remember in which one...:(