Hope
From Tardis Wiki, the free Doctor Who reference
Hope was an emotion which the Twelfth Doctor claimed was hard to resist. (TV: The Eaters of Light)
After the death of Lucie Miller, the Eighth Doctor found himself looking for hope. (AUDIO: The Great War)
When Kenossium told the Eleventh Doctor that the Time Lords would have nothing should he place Gallifrey in a pocket universe, he responded that they would have hope, something which they currently did not possess. (TV: The Day of the Doctor)