In the rest of his psychology and ethics the anonymous author follows Platonic theories, modified now and then in the manner of Aristotle. Thus we are told that the soul consists of three powers, or three souls, the vegetative, the animal and the rational. We learn of the existence of the vegetative soul from the nourishment, growth and reproduction evidenced by the individual. The animal soul shows its presence in the motions of the body. The existence of the rational soul we have already shown from the attributes of knowledge and ignorance. The vegetative soul comes from certain spheral influences, themselves due to the universal soul, and ultimately to the will of God. It is the first of the three to make its appearance in the body. It is already found in the embryo, to which it gives the power of motion in its own place like the motion of a plant or tree. Its seat is in the liver, where the growth of the embryo begins. Its function ceases about the twentieth year, when the growth of the body reaches its limit. The animal soul springs from the heart. Its functioning appears after birth when the child begins to crawl, and continues until the person loses the power of locomotion in old age. The rational soul resides in the middle of the brain. She knows all things before joining the body, but her knowledge is obscured on account of the material coverings which she receives on her way down from her divine source.[143] The virtue of the vegetative soul is temperance; of the animal soul, courage; of the rational soul, wisdom. When these are harmoniously combined in the individual, and the two lower souls are controlled by the higher, there results the fourth virtue, which is justice, and which gives its possessor the privilege of being a teacher and a leader of his people. In Moses all these qualities were exemplified, and Isaiah (11, 1-4) in describing the qualities of the Messianic King also enumerates these four cardinal virtues. "The spirit of wisdom and understanding" represents wisdom, "the spirit of counsel and strength" stands for courage; "the spirit of knowledge and fear of the Lord" denotes temperance; and justice is represented in the phrase, "and he will judge the poor with righteousness."[144]