Logic

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)