Logic

Logic, according to the Time Lord Astrolabus and the Lord of Life Voyager, was "a new toy". It claimed that the world had no end and that the Earth was round. The material existence of the edge of the universe proved that even in the Doctor's era, logic was not all-encompassing. (COMIC: Voyager)

The Cyber-tomb on Telos was based on symbolic logic. (TV: The Tomb of the Cybermen)

The Second Doctor told Zoe Heriot that logic merely enabled one to be wrong with authority. (TV: The Wheel in Space)

According to the Sixth Doctor, the only logic in the Matrix was that there was not any logic. (TV: The Ultimate Foe)

In the 40th century, the android Mark Seven's emotion circuit was subservent to his relentless logic. (AUDIO: The Destroyers)