So much and a great deal more of a similar kind is shown by direct observation of children, and by consideration of clear memories of childhood, uninfluenced by any analysis. Among other things you will infer from this that a child’s position in the sequence of brothers and sisters is of very great significance for the course of his later life, a factor to be considered in every biography. What is even more important, however, is that in the face of these enlightening considerations, so easily to be obtained, you will hardly recall without smiling the scientific theories accounting for the prohibition of incest. What has not been invented for this purpose! We are told that sexual attraction is diverted from the members of the opposite sex in one family owing to their living together from early childhood; or that a biological tendency against in-breeding has a mental equivalent in the horror of incest! Whereby it is entirely overlooked that no such rigorous prohibitions in law and custom would be required if any trustworthy natural barriers against the temptation to incest existed. The opposite is the truth. The first choice of object in mankind is regularly an incestuous one, directed to the mother and sister of men, and the most stringent prohibitions are required to prevent this sustained infantile tendency from being carried into effect. In the savage and primitive peoples surviving to-day the incest prohibitions are a great deal stricter than with us; Theodor Reik has recently shown in a brilliant work that the meaning of the savage rites of puberty which represent rebirth is the loosening of the boy’s incestuous attachment to the mother and his reconciliation with the father. Mythology will show you that incest, ostensibly so much abhorred by men, is permitted to their gods without a thought; and from ancient history you may learn that incestuous marriage with a sister was prescribed as a sacred duty for kings (the Pharaohs of Egypt and the Incas of Peru); it was therefore in the nature of a privilege denied to the common herd.