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.]

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

The Notebooks of Leonardo Da Vinci Complete