He taught that in man was “the immortal principle of the soul,” a mortal body, and a “separate mortal kind of soul,” which was placed in a separate receptacle of the body from the other; the immortal part was in the head (_Timæus_ xix., xx.) the other in the trunk (xliv.). Nothing is plainer than that Plato regarded the interior man as constituted of two parts--one always the same, formed of the same entity as Deity, and one mortal and corruptible. “Plato and Pythagoras,” says Plutarch, “distribute the soul into two parts, the rational (noëtic) and irrational (_agnoia_); that that part of the soul of man which is rational, is eternal; for though it be not God, yet it is the product of an eternal deity, but that part of the soul which is divested of reason (_agnoia_) dies.” “Man,” says Plutarch, “is compound; and they are mistaken who think him to be compounded of two parts only. For they imagine that the understanding is a part of the soul, but they err in this no less than those who make the soul to be a part of the body, for the understanding (_nous_) as far exceeds the soul, as the soul is better and diviner than the body. Now this composition of the soul (φυχη) with the understanding (νοῦς) makes reason; and with the body, passion; of which the one is the beginning or principle of pleasure and pain, and the other of virtue and vice. Of these three parts conjoined and compacted together, the earth has given the body, the moon the soul, and the sun the understanding to the generation of man.