This is a compilation of information from several older works, which have been brought together to explain this most important consideration in the spiritual life. We begin with a short consideration from Father Scaramelli, who died in 1752. He wrote a four volume work, Directorium Asceticum, which is an excellent treatise on the spiritual life. He touches on the four temperaments briefly. We will expand with the thoughts of Father John Henry Schagemann CSSR from his work, Manual of Self-Knowledge and Christian Perfection. This work is in two parts the first on the Four Temperaments and the balance is a excellent summary of the spiritual life. The first part of this 1913 work is reproduced here. The balance of this work is inspired by Konrad Hock, who wrote The Four Temperaments. There is a great deal of interest in self-examination in these days and the four temperaments are a great guide to understanding ourselves, our strengths and our weaknesses. Some misuse this information in order to find an excuse for sin, but there is no excuse for sin. Knowing our temperament, we can know where our strengths and weaknesses lie and with the help of God over come our weaknesses and build upon our strengths The four temperaments are based upon the four humors ancient philosophers believed exist in the human body: Melancholy, (Melancholic) Phlem, (Plegmatic) Blood (Sanguine) Choler (Choleric or Billious) We begin with a test to determine our temperament, so we can know where we stand entering into our study.