Human body. Historical artwork (c. 1485-1490) of the proportions of the human body by the Italian artist, engineer and scientist Leonardo da Vinci (1452-1519). This artwork, taken from one of da Vinci's notebooks, illustrates ideas of the ancient Roman architect Vitruvius about the ratios of various different body measurements. Also seen is Leonardo's mirror writing. He wrote backwards with his left hand to achieve this script. Leonardo habitually wrote like this in his notebooks. This may have been to prevent the theft of his ideas or to avoid charges of religious heresy due to conflicts between his writings and the doctrine of the Catholic church.