"Doctor," yelled Donna in her wedding dress, "you can stop now."
In the recesses of his mind, he could hear Rose saying the same. It was after the invasion of the Sycorax on Christmas. They had just retreated into the TARDIS.
"Why do you think Harriet Jones…fell?" asked Rose.
"I think…she acted Class A human. She was faced with, well, impossible circumstances that she couldn't wrap her human head around. So she acted on instinct—and the human instinct is to defend, to an extent where it's murder, not defense."
"I might slap you," said Rose, "Human's aren't that weak."
"Maybe not every human," he conceded, "But Harriet Jones certainly was. Every being has some level of that instinct. It's natural."
"What about you then? Are you human? Cause you're always protecting us," she looked at him queerly, "Like that time with the Daleks. You were going to blow everything up. Sometimes you've got to stop, Doctor, or you'll turn into Harriet Jones."
Was he Harriet Jones now?
Immediately, his pride screamed no. He was better; he gave chances. Harriet Jones didn't give the Sycorax a chance to reform.
"No second chances, that's what sort of man I am."
Now, right now he could give Empress Racnoss a second chance to prove herself better. He could give her the chance Harriet Jones never gave the Sycorax.
The Doctor merely stood there, not attempting in any way to stop the building around him from drowning and burning at the same time. He used to have so much mercy, but Rose had gone and left to him to succumb to himself.
He wasn't Harriet Jones, oh no. He was much, much, worse.