This section is from the book "Leonardo Da Vinci: A Psychosexual Study Of An Infantile Reminiscence", by Sigmund Freud. Also available from Amazon: Leonardo da Vinci: A Psychosexual Study of an Infantile Reminiscence.
When we proceed furdier we come upon a communication which may raise to a certainty the probability that Leonardo knew die vulture fable. The erudite editor and commentator of Horapollo remarked in connection with the text (p. 172) cited before: Caeterurn hanc fahularn de vulturibus cupide amplexi sunt Patres Ecclesiastic!, utita argumento ex rerum natura petito refutarent eos, qui Virginis partum nega-bant; itaque apud omnes fere hujus reimentio occurit.
Hence die fable of the monosexuality and the conception of the vulture by no means remained an indifferent anecdote as in die case of the analogous fable of the scarebaeus beetles. The church fathers mastered it in order to have it ready as an argument from natural history against those who doubted sacred history." If according die best information from antiquity the vultures were directed to let themselves be impregnated by the wind, why should die same thing not have happened even once in a human female? On account of die usefulness of this argument church fadiers were "almost all" in the habit of relating this vulture fable, and now it can hardly remain doubtful that it also became known to Leonardo dirough such a powerful source.
The origin of Leonardo's vulture fantasy can be conceived in die following manner: While reading in the writings of a church father or in a book on natural science that the vultures are all females and knew that they could procreate without the cooperation of a male, a memory emerged in him which became transformed into diat fantasy, but which meant to say that he also had been such a vulture child, which had a mother but no father. An echo of pleasure which he experienced at his mother's breast was added to this in the manner as such old impressions alone can manifest diem-selves. The allusion to the idea of die Holy Virgin widi the child, formed by the authors, which is so dear to every artist, must have contributed to it to make diis fantasy seem to him valuable and important. Thus he came to identify himself with the Christ child, the comforter and savior, and not only of diis one woman.
When we break up an infantile fantasy we strive to separate the real memory content from the later motives which modify and distort die same. In the case of Leonardo we now diink that we know the real content of the fantasy. The replacement of die mother by the vulture indicates diat the child missed the father and felt himself alone widi his mother. The fact of Leonardo's illegitimate birdi fits in with his vulture fantasy; only on account of it was he able to compare himself with a vulture child. But we have discovered as the next definite fact from his youth that at the age of five years he had already been received in his fatiier's home; when this took place, whether a few months following his birth, or a few weeks before the taking of the assessment of taxes, is entirely unknown to us. The interpretation of the vulture fantasy then steps in and wants to tell us that Leonardo did not spend the first decisive years of his life with his father and his step-mother but with his poor, forsaken, real modier, so that he had time to miss his father. This still seems to be a rather meager and rather daring result of die psychoanalytic effort, but on further reflection it will gain in significance. Certainty will be strengthened by considering the actual relationships in Leonardo's childhood. According to the reports, his father Ser Piero da Vinci married die prominent Donna Albiera during the year of Leonardo's birth; it was to die childlessness of this marriage that the boy owed his legalized reception into his father's or rather grandfather's house during his fifth year. However, it is not customary to offer an illegitimate offspring to a young woman's care at the beginning of marriage when she is still expecting to be blessed with children. Years of disappointment must have elapsed before it was decided to adopt die probably handsomely developed illegitimate child as a compensation for legitimate children who were vainly hoped for. It harmonizes best with die interpretation of die vulture-fantasy, if at least diree years or perhaps five years of Leonardo's life had elapsed before he changed from his lonely mother to his father's home. But by then it had already become too late. In the first three or four years of life impressions are fixed and modes of reactions are formed towards the outer world which can never be robbed of their importance by any later experiences.
If it is true that incomprehensible childhood reminiscences and the person's fantasies based on them always bring out the most significant psychic development, then the fact corroborated by die vulture fantasy, that Leonardo passed die first years of his life alone with his mother must have been a most decisive influence on die formation of his inner life. Under the effect of this constellation it could not have been otherwise than that the child who in his young life encountered one problem more than other children, should have begun to ponder riddle and very passionately and thus should have become an investigator early in life. For he was tortured by the great questions, where do children come from and what has the father to do widi their origin.
The vague knowledge of this connection between his investigation and his childhood history later drew from him the exclamation diat it was destined that he should occupy himself deeply with die problem of the bird's flight, for already in his cradle he had been visited by a vulture. To trace the curiosity directed to the flight of the bird to infantile sexual investigation will be a later task which will not be difficult to accomplish.