In contradiction of the generally accepted view that left-handedness is congenitally determined, evidence is adduced that all children are congenitally ambidextrous, and left-handedness develops on the basis of unconscious motivation. That writing has come to symbolize coitus is suggested by a considerable mass of philological and other data. Because the connotations of 'left' as opposed to right are those of wrong, sinister, evil, to write with the left hand is to perform coitus in illicit fashion. Because writing is symbolically 'to plow the fields', writing illicitly is sowing 'into the holy field of the mother'; early man's fantasies, preserved in the words we use, dealt much more with agricultural terms than do ours today. This is reflected also in the farmer's supposition that a castrate is meek, good, and tame. The accused, the evil, the unchaste is the left-handed; his illicit Oedipal impulses have led him to select left-handedness, thereby acting out both the forbidden impulse and the punishment therefor, of being classed as a pariah.