The Doctor: Grenades. As insurance policy.
Paltraki: You think that's smart?
The Doctor: I think it's a precaution. I like precautions. Always take precautions. Especially when you don't know what you're doing.

Ryan: What happened to 'never do weapons'?
The Doctor: It's a flexible creed. Door, locks, walls, buildings. Fair game. If it can be rebuilt, I'll allow it.

Graham: He's the commander.
Ryan: Maybe he killed his own crew.
Graham: Always one for the cheery option.

Graham: And it has to be us does it? Answering these signals from this planet?
The Doctor: No, not at all. But everyone else has passed them by. Y'think we should do the same?

Andinio: It's time. You ready, Delph?
Delph: I don't think I am.
Andinio: Seventeen years is enough. This is what I've trained you for.
Delph: You call it training. I call it building doubt. Every lesson that you've given me, I feel like I've understood less, not more.
Andinio: Which is the point. The more we learn, the less we realize we know. This is our faith. This is our existence. The Creator would contend the world is not to be understood, only experienced.

You are the maddest, most beautiful thing I've ever experienced and I haven't even scratched the surface. I wish I could stay. But if either of us are going to survive, you're going to have to let me go and keep on being brilliant by yourself.

The Doctor

The Doctor: The Solitract is a frog? Who talks like Grace?
Solitract Frog: My own form is endless but this frog is a form that delights me as it once delighted Grace.
The Doctor: There's me thinking the day had no more surprises left.

This woman is clearly an alien force, collapsing two realities and impersonating your dead wife. Time to move on, mate!

The Doctor

She's not your wife! She's furniture with a pulse.

The Doctor

The Doctor: Solitract! It's a theory, a myth, a bedtime story my Gran used to tell me.
Yaz: You had a grandmother?
The Doctor: I had seven but Granny Five, my favorite, used to tell me about the Solitract.

The Doctor: What did he look like? This man.
Ribbons: No horns. One mouth. So ugly. Like you. But such nice big boots.

Ribbons: Bird is lunch. Maybe codger is tea.
Graham: Who are you calling a codger? It's you who stinks of his own wee.
Ribbons: That's not my wee.
The Doctor: Let him go cause you do not want those words to be your last ones.

Doctor Who Quotes

Only in darkness are we revealed. [...] Goodness is not goodness that seeks advantage. Good is good in the final hour, in the deepest pit, without hope, without witness, without reward. Virtue is only virtue in extremis. This is what *he* believes, and this is the reason above all I love him, my husband. My madman in a box. My Doctor.

Nardole [quoting River Song]

Gallifreyan Soldier: There was a saying, sir, in the Time War.
Lord President Rassilon: A saying?!
Gallifreyan Soldier: First thing you notice about the Doctor of War is that he is unarmed. For many, it's also the last.