By some accounts, being a slave in late republican and Imperial rome is not such a bad lot - so long as you are brought into a wealthy household. Nonetheless, we know many slaves were sent to mining camps. This was understood to effectively be a death sentence.
How Roman society determine which path a Slave would take, and was there any legal/moral distinction between the two?
Hey,
You're right in saying that the treatment of a slave was completely up to his or her owner.
Skilled slaves were sometimes used to help keep the machinery of bureaucracy and administration working. They would need to have been well educated and literate. So literacy can be viewed as a potential path setter. Hellenic slaves too may have often found themselves in this sort of roles.
We know that Cato the Elder would acquire young slaves, train and educate them, and then sell them on for a profit. They were an investment, and would be treated as such.
So literacy for a start seems to have separated 'white collar' slaves from those in the mines.
Alston describes this nicely - 'The Romans were unsentimental about slaves. Slaves were economic units and counted as such'.
The vast majority of slaves in Italy must have worked on the land, which would have been ok (as slaving goes)
Those condemned to ergastulae, or slave prisons, would have had a far grimmer life, likewise the same with those slaves condemned to the mines. They were disposable.
Hope this helps somewhat :)
Edit: forgot to put in my sources!
Kamm, A. 1995. The Romans, an introduction
Alston, R. 1998. Roman History AD 14 - 117