From "Doctor Who: The Tyrant of France (#1.40)"
We in Paris are aware of the danger, Citizen. We live in troubled times. There is much, much work to be done, work that is constantly delayed by the need to ferret out the traitors that we harbor in our midst...
Is there really such a need, Citizen Robespierre? Hmm? I mean, what can this Reign Of Terror possibly gain? For every opponent you put to the guillotine, two more will spring up!