Page "The Parting of the Ways" Paragraph 14

Rose's actions create a predestination paradox.

The words " Bad Wolf " tell her to try to get back to the Doctor, and her doing so gives her the ability to leave the words through time as messages to herself, which she then does.

Although it can be argued that the phrase " Bad Wolf " originates with the Badwolf Corporation, it can also be argued that she somehow prompted the creation of the phrase through her powers in the first place, thereby also introducing an ontological paradox.

Ontological paradoxes were explored in " Blink ", where the Doctor explains that space-time is not strictly cause-to-effect, and serve as a major plot device in " Time Crash ".

The Doctor himself moves in a fictitious five-dimensional setting ( The Space Museum, 1964 ), and perhaps a six-dimensional setting ( Inferno, 1970 ).