Privilege
The Twelfth Doctor believed that the value of any given society was truly measured by the value it placed on a life, in particular one without privilege. His view of progress was one which considered how a culture treated those in the lowest rungs of their society, rather than focusing on mere industry or wealth. (TV: Thin Ice)
The boy who died on the river — that boy's value is your value. That's what defines an age. That's what defines a species.
Indeed, the First Doctor himself had been born into wealth and privilege. Robin Hood compared his own origins to the Twelfth Doctor's. He understood that, like himself, the Doctor had found it too hard to bear the "plight of the oppressed", and so, refusing to stand idly by, he ran off in the TARDIS to fight injustice in his own way. (TV: Robot of Sherwood)
On becoming a renegade Time Lord and running away from Gallifrey in a stolen time capsule, the Doctor's Prydonian privileges were revoked. (TV: Death in Heaven) According to the Sixth Doctor, however, he would have been considered plebeian. (AUDIO: Cortex Fire)
The Eighth Doctor remembered growing up on Gallifrey with all the privileges that came with an "important", political family. (AUDIO: Must-See TV)
In its original incarnation, Ravenscaur School was a school for the underprivileged. After the death of founder Hamish Ravenscaur, his descendants turned the school into one for the rich and privileged. (COMIC: Clara Oswald and the School of Death)
