The quote claims that it is impossible to find truth through our perceptions; however that is an oxymoron since the statement itself implies itself to be a truth while denying the possibility of truth.
"Truth fears no questions" because no matter how the truth is questioned it wont chance the fact that it still is the truth. If something happened and person asked you if you're sure, then it would...
While the origins of the quote are questionable,it most certainly did not originate with Dr. Phil. Most frequently it is attributed to Eleanor Roosevelt or Col. Jeff Cooper