T'plana-Hath's Razor was a concept known to the Vulcan civilization. It postulated the idea that the simplest explanation was also likely to had been the most logical one.

In 2298, Doctor T'Lavik believed that the suspected telepathic contact between Tuvok and Tholian Ambassador Kasrene was simply a result of the injuries that Tuvok had sustained. This was based on the fact that the Tholian Lattice was not receptive to the Vulcan mind meld and by calling upon T'Plana-Hath's Razor, the simplest explanation was the most logical. (TLE novel: The Sundered)

Presumably, it's attributed to the philosopher T'Plana Hath.

See also: Sutak's Fifth Principle; Occam's Razor