The Video discusses using the Quran as a yardstick to measure and evaluate other things. Now that they have verified that the Quran is from Allah through investigation and contemplation, they will reject anything that contradicts the Quran. This is because they now have a perfect and confirmed standard in the Quran to use for measurement. They question whether free thought has any meaning once the truth has been found. It is not sensible, according to the speaker, to reject the truth once it has been confirmed just in the name of free thought.