The Secret Lives of Slaves

Homer was a very shrewd observer of human life and personality.  This is from Fagles' translation of Book XIX, where Achilles and the Greeks all mourn the death of Achilles' friend Patroclus:

And so Briseis returned, like golden Aphrodite,

but when she saw Patroclus lying torn by the bronze

she flung herself on his body, gave a piercing cry 

 and with both hands clawing deep at her breasts, 

her soft throat and lovely face, she sobbed, 

a woman like a goddess in her grief,

...

"So now I mourn your death—I will never stop— 

you were always kind." 

                                        Her voice, rang out in tears 

and the women wailed in answer, grief for Patroclus  

calling forth each woman's private sorrows.

Whoever he was, Homer understood the secret lives of slaves, society's losers without control over their lives or even their own bodies.  City taken, men killed, the surviving women were distributed among the victorious warriors: to launder their clothes, prepare their food, and warm their beds - sometimes for the rest of their lives.  They had no easy outlet for their sorrows, until a great man mourned.  Then they were called on to mourn likewise.

Brises, though a slave of the Greeks, had her reasons for being grateful to Patroclus and lamented his loss.  The other slave women had no such feelings to draw upon, though they had no trouble finding things to lament.  See how easy and quickly the wails came forth - in immediate echo to Brises'.

The powerful often exert a powerful control over those around them, but they can never possess the hearts of the humble.  The great and mighty can never be sure what thoughts hide behind a crying or smiling face.

Psalms 137:1-4 is also very relevant:

By the rivers of Babylon, there we sat down, yea, we wept, when we remembered Zion.
We hanged our harps upon the willows in the midst thereof.
For there they that carried us away captive required of us a song; and they that wasted us required of us mirth, saying, Sing us one of the songs of Zion.
How shall we sing the Lord’s song in a strange land?