that there never could have been such forms. This latter is a rational truth. So by means of scientific facts, a new plane of rational thought is formed. This is the Rational plane, a discrete degree higher than the Scientific plane. It is formed from rational knowledge and its life.
Not only is it evident that these three planes exist in the human constitution, but also we know that they are developed in the order given, and are related as cause and effect. The infant lives in the Sensual plane until that is formed sufficiently to obtain scientific facts, for there is nothing else for it to live in. The child can not live above the Scientific plane until the Rational is formed by the use of scientific facts. The infant experiences sensation, and forms the Sensual plane. The child asks the what, and forms the Scientific plane. The youth inquires of the why, and forms the Rational plane. When these three planes are formed, there are three distinct orders of life to enjoy, that of sensation, elevated and corrected by mental development; that of facts or science, embracing all the facts of natural science; and that of rational truths. These three discrete planes form and constitute the Natural Mind. The Natural Mind is that which is frequently though vaguely designated as the lower nature of man. The Natural Mind is the natural man.
