| We will control|
what you think with
|Here's how we do it|
It refers to a quality that statements can have where they "seem true", or "should be true", or "would (give good story / support my agenda / impress people) if they were true" ... without any actual worry over whether they would be judged to be "actually" true by skeptical and disinterested observers.
Stephen uses his gut rather than his head to determine the truthiness of a given statement.