Imagination

One's imagination referred to their ability to produce ideas in their mind.

Psychic paper worked based off the imagination of the person it was shown to. (TV: Flatline) When the Tenth Doctor showed it to Anya Kingdom and Mark Seven, he noted that the former had a bizarre imagination when she read it as "Grand High Prince of Skaro" and noted that the latter's could use some work when the android read it as "the Doctor". (AUDIO: The House of Kingdom) When Clara Oswald used to it pass herself off as a health and safety official, Fenton saw the paper as blank, something the Twelfth Doctor credited to his highly unimaginative mind. (TV: Flatline)

Charles Dickens wondered if his imagination had gone stale. (TV: The Unquiet Dead)

A technician told a UNIT officer not to let her imagination run away with her. (TV: Spearhead from Space)

The Krillitanes needed children rather than adults to unlock the Skasis Paradigm because of their imagination. (TV: School Reunion)

When the Fifth Doctor heard the White Guardian in his TARDIS, he wondered if it was just his imagination. (TV: Enlightenment)

The Cult of Skaro was formed to imagine new ways for the Daleks to survive. (TV: Doomsday)

A planet was destroyed when the imagination of the Doctor's TARDIS overloaded the Ch'otterai. (PROSE: The Mystery of the Haunted Cottage)

Sperantium was the chemical that fuelled imagination. It was harvested by Ronan Sumners, who used it to power New Port City's teleportation system. (PROSE: Gatecrashers)