The Notebooks of Leonardo Da Vinci Read Online Free PDF

(!) in 1500 (see H. LUDWIG. L. da Vinci: Das Buch van
der Malerei . Vienna 1882 III, 7 and 8).]
    The use of the book on Painting.
    18.
    These rules are of use only in correcting the figures; since every
man makes some mistakes in his first compositions and he who knows
them not, cannot amend them. But you, knowing your errors, will
correct your works and where you find mistakes amend them, and
remember never to fall into them again. But if you try to apply
these rules in composition you will never make an end, and will
produce confusion in your works.
    These rules will enable you to have a free and sound judgment; since
good judgment is born of clear understanding, and a clear
understanding comes of reasons derived from sound rules, and sound
rules are the issue of sound experience—the common mother of all
the sciences and arts. Hence, bearing in mind the precepts of my
rules, you will be able, merely by your amended judgment, to
criticise and recognise every thing that is out of proportion in a
work, whether in the perspective or in the figures or any thing
else.
    Necessity of theoretical knowledge (19. 20).
    19.
OF THE MISTAKES MADE BY THOSE WHO PRACTISE WITHOUT KNOWLEDGE.
    Those who are in love with practice without knowledge are like the
sailor who gets into a ship without rudder or compass and who never
can be certain whether he is going. Practice must always be founded
on sound theory, and to this Perspective is the guide and the
gateway; and without this nothing can be done well in the matter of
drawing.
    20.
    The painter who draws merely by practice and by eye, without any
reason, is like a mirror which copies every thing placed in front of
it without being conscious of their existence.
    The function of the eye (21-23).
    21.
INTRODUCTION TO PERSPECTIVE:—THAT IS OF THE FUNCTION OF THE EYE.
    Behold here O reader! a thing concerning which we cannot trust our
forefathers, the ancients, who tried to define what the Soul and
Life are—which are beyond proof, whereas those things, which can at
any time be clearly known and proved by experience, remained for
many ages unknown or falsely understood. The eye, whose function we
so certainly know by experience, has, down to my own time, been
defined by an infinite number of authors as one thing; but I find,
by experience, that it is quite another. [Footnote 13: Compare the
note to No. 70.]
    [Footnote: In section 13 we already find it indicated that the study
of Perspective and of Optics is to be based on that of the functions
of the eye. Leonardo also refers to the science of the eye, in his
astronomical researches, for instance in MS. F 25b ' Ordine del
provare la terra essere una stella: Imprima difinisce l'occhio' ,
&c. Compare also MS. E 15b and F 60b. The principles of astronomical
perspective.]
    22.
    Here [in the eye] forms, here colours, here the character of every
part of the universe are concentrated to a point; and that point is
so marvellous a thing … Oh! marvellous, O stupendous Necessity—by
thy laws thou dost compel every effect to be the direct result of
its cause, by the shortest path. These [indeed] are miracles;…
    In so small a space it can be reproduced and rearranged in its whole
expanse. Describe in your anatomy what proportion there is between
the diameters of all the images in the eye and the distance from
them of the crystalline lens.
    23.
OF THE 10 ATTRIBUTES OF THE EYE, ALL CONCERNED IN PAINTING.
    Painting is concerned with all the 10 attributes of sight; which
are:—Darkness, Light, Solidity and Colour, Form and Position,
Distance and Propinquity, Motion and Rest. This little work of mine
will be a tissue [of the studies] of these attributes, reminding the
painter of the rules and methods by which he should use his art to
imitate all the works of Nature which adorn the world.
    24.
ON PAINTING.
    Variability of the eye.
    1st. The pupil of the eye contracts, in proportion to the increase
of light which is reflected in it. 2nd. The pupil of the