In a piece that struck me as overwritten:
"We must look up from our literary games and see what is almost too big to be seen—the fact of slavery, towering above us like the trees of an immense forest of unfreedom that covered the Roman world."
I'm not sure what is too big to see about this, but there was a lot of slavery in Rome, it's true. It wasn't quite the same thing as American slavery, it wasn't racially based, but it was slavery.
The author is making the point that the apparent sexual freedom of the Romans had a lot to do with their freedom to tell their slaves what to do.
In a fresco, it's not always easy to see
who is the master and who is free.