Robert Burns

Robert Burns was an author who was born in 1759. The Second Doctor once offered up a bit of Burns — "Nae man can tether time nor tide" — in response to Jamie McCrimmon's initial incredulity at the notion that the TARDIS crew had no idea where in time or space they might land. As Jamie came from 1746, though, he had no idea who Burns was. (DW: The Underwater Menace)

Behind the scenes
The phrase "tim'rous beastie", used by the Tenth Doctor in Tooth and Claw to describe Rose Tyler and by Jackson Lake in The Next Doctor to describe Rosita Farisi, would seem to be lifted from a Robert Burns poem. However, no connection is explicitly noted in the script of either episode.