Man on the Clapham Omnibus (concept)
From Tardis Wiki, the free Doctor Who reference
The Man on the Clapham Omnibus is a legal concept of a man who is a reasonable, virtuous, prudent observer of the case under consideration. It was personified by members of Faction Paradox as the Man on the Clapham Omnibus and eventually imprisoned in the Boulevard of Alternate Brutalities. (PROSE: A Reasonable Man)