Sri Aurobindo
Letters of Sri Aurobindo
Volume IV - Part 3
You are very much behind the times. Do you not know that even 
many doctors now admit and write it publicly that medicines are an element but only one and that the psychological element counts as much and even more? I have heard that from doctors often and read it over reputable medical signatures. And among the psychological elements, they say, one of the most important is the doctor’s optimism and self-confidence, (his faith, what? it is only another word for the same thing) and the confidence, hope, helpful mental atmosphere he can inspire in or around his patient. I have seen it stated categorically that a doctor who can do that is far more successful than one who knows Medicine better but cannot.