The question, What is Truth, is answered by demonstration,--by healing both disease and sin; and this demonstration shows that Christian healing confers the most health and makes the best men.
 
Truth is affirmative, and confers harmony. All metaphysical logic is inspired by this simple rule of Truth, which governs all reality. By the truthful arguments you employ, and especially by the spirit of Truth and Love which you entertain, you will heal the sick.
 
Mary Baker Eddy, Science and Health With Key to the Scriptures, p.viii,418