If you take Nash book 'Leaders'. I like Nash, because he is reliable. There is nothing in Nash that I have read, especially his materia medica, that you can remove, that you can say he is wrong for it, or is not confirmed. It is like each thing that he says about his materia medica is something that is confirmed it is like a brick of a building. You cannot change, you can only build on it, but you cannot remove. There are other materia medica, you read it and you cannot associate with it at all.

(Dr. Andre Saine)