Leonardo da Vinci’s ‘Vitruvian Man’ has always been a complete fascination for me. Given my mathematics background, I suppose it’s only natural. Additionally, an argument could be made that my homosexuality also led to a keen interest in male anatomy. But, honestly, my interest in DaVinci’s work goes much deeper than either of these hypotheses.

Most scholars agree that da Vinci’s own interest in anatomy and proportion is clearly documented in his writings. In the case of ‘Vitruvian Man’, the origins can be traced back to De Architectura as written by the ancient Roman Vitruvius:

Vitruvius, De Architectura:
THE PLANNING OF TEMPLES

1. The planning of temples depends upon symmetry: and the method of this architects must diligently apprehend. It arises from proportion (which in Greek is called analogia). Proportion consists in taking a fixed module, in each case, both for the parts of a building and for the whole, by which the method of symmetry is put to practice. For without symmetry and proportion no temple can have a regular plan; that is, it must have an exact proportion worked out after the fashion of the members of a finely-shaped human body.

2. For Nature has so planned the human body that the face from the chin to the top of the forehead and the roots of the hair is a tenth part; also the palm of the hand from the wrist to the top of the middle finger is as much; the head from the chin to the crown, an eighth part; from the top of the breast with the bottom of the neck to the roots of the hair, a sixth part; from the middle of the breast to the crown, a fourth part; a third part of the height of the face is from the bottom of the chin to the bottom of the nostrils; the nose from the bottom of the nostrils to the line between the brows, as much; from that line to the roots of the hair, the forehead is given as the third part. The foot is a sixth of the height of the body; the cubit a quarter, the breast also a quarter. The other limbs also have their own proportionate measurements. And by using these, ancient painters and famous sculptors have attained great and unbounded distinction.

3. In like fashion the members of temples ought to have dimensions of their several parts answering suitably to the general sum of their whole magnitude. Now the navel is naturally the exact centre of the body. For if a man lies on his back with hands and feet outspread, and the centre of a circle is placed on his navel, his figure and toes will be touched by the circumference. Also a square will be found described within the figure, in the same way as a round figure is produced. For if we measure from the sole of the foot to the top of the head, and apply the measure to the outstretched hands, the breadth will be found equal to the height, just like sites which are squared by rule.

4. Therefore if Nature has planned the human body so that the members correspond in their proportions to its complete configuration, the ancients seem to have had reason in determining that in the execution of their works they should observe an exact adjustment of the several members to the general pattern of the plan. Therefore, since in all their works they handed down orders, they did so especially in building temples, the excellences and the faults of which usually endure for ages.

Book 3, c. I1

There is little doubt that the first appearance of ‘Vitruvian Man’ in da Vinci’s notebooks was circa 1490. The notations accompanying the sketch were written in mirror writing and detail the following proportionalities:

–a palm is the width of four fingers
–a foot is the width of four palms
–a cubit is the width of six palms
–a man’s height is four cubits (and thus 24 palms)
–a pace is four cubits
–the length of a man’s outspread arms is equal to his height
–the distance from the hairline to the bottom of the chin is one-tenth of a man’s height
–the distance from the top of the head to the bottom of the chin is one-eighth of a man’s height
–the maximum width of the shoulders is a quarter of a man’s height
–the distance from the elbow to the tip of the hand is one-fifth of a man’s height
–the distance from the elbow to the armpit is one-eight of a man’s height
–the length of the hand is one-tenth of a man’s height
–the distance from the bottom of the chin to the nose is one-third of the length of the face
–the distance from the hairline to the eyebrows is one-third of the length of the face
–the length of the ear is one-third of the length of the face

Of course, anthropometry has shown that there is no such thing as a universal proportion for the human body. Many historians have assumed that Vitruvius’ writing were describing an “ideal” human of given proportionalities. Whatever the case, it is intriguing to note that in formulating his ‘Vitruvian Man’, da Vinci did not strictly adhere to Vitruvius’ exhaustive mathematical calculations. Man and nature were both important to da Vinci. In tracing the whole of his work, his artistic vision lay inherent in the definition of the purpose of his art–that is to paint ‘man and the intention of his soul’ in terms of ‘attitudes and movements of the limbs’. The pursuit of this goal led him to analyze the postures and gestures of men’s bodies in terms of their mathematical and mechanical laws. It also led to examinations of the mechanical instruments responsible for those gestures and attitudes. Da Vinci literally dissected the human body to reveal the forms of its muscles, with the mission of tracing the source of their forces back to the spinal cord and brain.

To this end, the rendering of da Vinci’s ‘Vitruvian Man’ is different from other interpretations in that the circle and square image are overlaid on one another to form one image. More significantly, da Vinci made a key adjustment that others had not done which had heretofore led to disproportionate appendages. It is Leonardo, not Vitruvius, who points out that “If you open the legs so as to reduce the stature by one-fourteenth and open and raise your arms so that your middle fingers touch the line through the top of the head, know that the centre of the extremities of the outspread limbs will be the umbilicus, and the space between the legs will make and equilateral triangle”. This provides one of his simplest illustrations of a shifting ‘centre of magnitude’ without a corresponding change of ‘centre of normal gravity’. This remains passing through the central line from the pit of the throat through the umbilicus and pubis between the legs. Leonardo repeatedly distinguishes these two different ‘centres’ of a body, i.e., the centers of ‘magnitude’ and ‘gravity’.

By making the seemingly simple observation that the circle and square cannot have the same centers–the circle’s center being the umbilicus and the square’s center being placed lower in the anatomy–da Vinci created the symbol for the implied symmetry of the human body–and by extension in his body of work the symmetry of the universe.

Leonardo da Vinci’s groundbreaking ‘Vitruvian Man’ is one of the world’s most referenced and reproduced artistic images.