A Treatise on Painting

by da Vinci Leonardo

In general, the dimensions of the human body are to be considered in the length, and not in the breadth; because in the wonderful works of Nature, which we endeavour to imitate, we cannot in any species find any one part in one model precisely similar to the same part in another. Let us be attentive, therefore, to the variation of forms, and avoid all monstrosities of proportion; such as long legs united to short bodies, and narrow chests with long arms. Observe also attentively the measure of joints, in which Nature is apt to vary considerably; and imitate her example by doing the same.

Chap. VIII.—Motion, Changes, and Proportion of Members.

The measures of the human body vary in each member, according as it is more or less bent, or seen in different views, increasing on one side as much as they diminish on the other.

Chap. IX.—The Difference of Proportion between Children and grown Men.

In men and children I find a great difference between the joints of the one and the other in the length of the bones. A man has the length of two heads from the extremity of one shoulder to the other, the same from the shoulder to the elbow, and from the elbow to the fingers; but the child has only one, because Nature gives the proper size first to the seat of the intellect, and afterwards to the other parts.

Chap. X.—The Alterations in the Proportion of the human Body from Infancy to full Age.

A man, in his infancy, has the breadth of his shoulders equal to the length of the face, and to the length of the arm from the shoulder to the elbow, when the arm is bent [2]. It is the same again from the lower belly to the knee, and from the knee to the foot. But, when a man is arrived at the period of his full growth, every one of these dimensions becomes double in length, except the face, which, with the top of the head, undergoes but very little alteration in length. A well-proportioned and full-grown man, therefore, is ten times the length of his face; the breadth of his shoulders will be two faces, and in like manner all the above lengths will be double. The rest will be explained in the general measurement of the human body[3].

Chap. XI.—Of the Proportion of Members.

All the parts of any animal whatever must be correspondent with the whole. So that, if the body be short and thick, all the members belonging to it must be the same. One that is long and thin must have its parts of the same kind; and so of the middle size. Something of the same may be observed in plants, when uninjured by men or tempests; for when thus injured they bud and grow again, making young shoots from old plants, and by those means destroying their natural symmetry.