Mystery and Excellence on The Human Body - Extracts From Leonardo Da Vinci's Notebooks

Leonardo's drawing:

study of the shoulder, the arm and one foot

Extracts from 

Leonardo da Vinci's Notebooks

How it is necessary for the painter to know the inner structure of  man.

The painter who has a knowledge of the nature of the sinews, muscles,  and tendons will know very well in the movement of a limb how many  and which of the sinews are the cause of it, and which muscle by  swelling is the cause of the contraction of that sinew; and which sinews  expanded into most delicate cartilage surround and support the said  muscle.

In fifteen entire figures there shall be revealed to you the microcosm on the same plan as before me was adopted by Ptolemy in his  cosmography; and I shall divide them into limbs as he divided the  macrocosm into provinces; and I shall then define the functions of the  parts in every direction, placing before your eyes the representation of  the whole figure of man and his capacity of movements by means of  his parts. And would that it might please our Creator that I were able to  reveal the nature of man and his customs even as I describe his figure.

As regards the disposition of the limbs in movement you will have  to consider that when you wish to represent a man who for some reason has to turn backwards or to one side you must not make him move  his feet and all his limbs towards the side to which he turns his head.  Rather must you make the action proceed by degrees and through the  different joints, that is those of the foot, the knee, the hips and the neck.  If you set him on the right leg, you must make his left knee bend  inwards and his left foot slightly raised on the outside; and the nape of  the neck is in a line directly over the outer ankle of the left foot. And  the left shoulder will be in a perpendicular line, above the toes of the  right foot. And always set your figures so that the side to which the  head turns is not the side to which the breast faces, since nature for our  convenience has made us with a neck which bends with ease in many

directions as the eye turns to various points and the other joints are  Partly obedient to it.

Of human movement

When you wish to represent a man in the act of moving some weight,  reflect that these movements are to be represented in different directions. A man may stoop to lift a weight with the intention of lifting it as  he straightens himself; this is a simple movement from below upwards; or he may wish to pull something backwards, or push it forward or  draw it down with a rope that passes over a pulley. Here you should  remember that a man's weight drags in proportion as the centre of his  gravity is distant from that of his support, and you must add to this the  force exerted by his legs and bent spine as he straightens himself.

The sinew which guides the leg, and which is connected with the  patella of the knee, feels it a greater labour to carry the man upwards in  proportion as the leg is more bent; the muscle which acts upon the  angle made by the thigh where it joins the body has less difficulty and  less weight to lift, because it has not the weight of the thigh itself. And  besides this its muscles are stronger being those which form the buttock.

The first thing that the man does when he ascends by steps is to free  the leg which he wishes to raise from the weight of the trunk which is  resting upon this leg, and at the same time he loads the other leg with  his entire weight including that of the raised leg. Then he raises the leg  and places the foot on the step where he wishes to mount; having done  this he conveys to the higher foot all the weight of the trunk and of the  leg and leaning his hand upon his thigh, thrusts the head forward and  moves towards the point of the higher foot, while raising swiftly the  heel of the lower foot; and with the impetus thus acquired he raises  himself up; and at the same time by extending the arm which was resting upon his knee he pushes the trunk and head upwards and thus  straightens the curve of his back.

There are [four] principle simple movements in the flexion per formed by the joint of the shoulder, namely when the arm attached to  the same moves upward or downwards or forward or backward. One  might say, though, that such movements are infinite. For if we turn our  shoulder towards a wall and describe a circular figure with our arm we  shall have performed all the movements contained in the said shoulder.  And, since [every circle is] a continuous quantity, the movement of the  arm [has produced] a continuous quantity. This movement would not  produce a continuous quantity were it not guided by the principle of

continuation. Therefore, the movement of that arm has been through all  the parts of the circle. And as the circle is divisible in infinitum the  variations of the shoulder have been infinite.

The Tongue: Of the muscles which move the tongue

No organ needs so great a number of muscles as the tongue, — of these  twenty-four were already known apart from the others that I have discovered; and of all the members moved by voluntary action this  exceeds all the rest in the number of its movements.... The present task  is to discover in what way these twenty-four muscles are divided or  apportioned in the service of the tongue in its necessary movements  which are many and varied; and in addition it has to be seen in what  manner the nerves descend to it from the base of the brain, and how  they pass into this tongue distributing themselves and breaking into  ramifications. And it must further be noted how these twenty-four muscles convert themselves into six in the formation they make in the  tongue. Moreover, you should show whence these muscles have their  origin, that is some in the vertebrae of the neck... some in the maxilla,  and some on the trachea.... And similarly how the veins nourish them  and how the nerves give them sensation....

The tongue works in the pronunciation and articulation of the syllables which constitute the words. This tongue is also employed during

Study of the tongue

the necessary revolutions of the food in the process of mastication and  in the cleansing there from of the inside of the mouth and teeth. Its principal movements are seven....

Consider well how by the movement of the tongue, with the help of the lips and teeth, the pronunciation of all the names of things is known  to us; and how the simple and compound words of a language reach  our ears by means of this instrument; and how these, if there were a  name, for all the effects of nature, would approach infinity, together  with the countless things which are in action and in the power of  nature; and these man does not express in one language only but in a  great number, and these also tend to an infinity; because they vary continually from century to century, and from one country to another,  through the intermingling of the peoples who by wars and other mis-chances continually mix with one another; and the same languages are  liable to pass into oblivion, and they are mortal like all created things; and if we grant that our world is everlasting, we shall say that these  languages have been, and still will be, of infinite variety, through the  infinite centuries which constitute infinite time. And this is not the case  with any other sense; for these are concerned only with such things as  nature continually produces; and the ordinary shapes of things created  by nature do not change, as from time to time do the things created by  man, who is nature's greatest instrument.

The Lips: Of the muscles which move the lips of the mouth

The muscles which move the lips of the mouth are more numerous in  man than in any other animal; and this is necessary for him on account  of the many action in which these lips are continually employed, as in  the four letters of the alphabet bfmp, in whistling, laughing, weeping,  and similar actions. Also in the strange contortions used by clowns when they imitate faces. 

What muscle is that which so tightens the mouth that its lateral boundaries come near together?

The muscles which tighten the mouth thus lessening its length are in the lips; or rather these lips are the actual muscles which close them selves. In fact this muscle alters the size of the lip below other muscles,  which are joined to it and of which one pair distends it and moves it to  laughter,... and the muscle which contracts it is the same of which the  lower lip is formed; and a similar process goes on simultaneously in

the upper lip. There are other muscles which bring the lips to a point; others that flatten them; others which cause them to curl back, others  that straighten them; others which twist them all awry; and others  which bring them back to the first position. So there always are as  many muscles as correspond to the various attitudes of these lips and as  many others that serve to reverse these attitudes; and these it is my purpose here to describe and represent in full, proving these movements  by means of my mathematical principles.

The Embryo

Though human ingenuity may make various inventions answering by  different machines to the same end, it will never devise an invention  more beautiful, more simple, more direct than does Nature; because in  her inventions nothing "is lacking, and nothing is superfluous. She  needs no counterpoise when she creates limbs fitted for movement in  the bodies of animals, but puts within them the soul of the body which  forms them, that is the soul of the mother which first constructs within  the womb the shape of man, and in due time awakens the soul that is to  be its inhabitant.

Extracts from the Notebooks of Leonardo da Vinci
selected & edited by Irma A. Richter, Oxford University Press.