19

Necessity of theoretical knowledge.

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.

Taken from The Notebooks of Leonardo da Vinci edited by Jean Paul Richter, 1880.

18 * 20
Notebooks of Leonoardo da Vinci
I: Prolegomena and General Introduction to the Book on Painting.
. . .
The author’s intention to publish his MSS.
1
The preparation of the MSS. for publication.
2
Admonition to readers.
3
The disorder in the MSS.
4
subjects..
5,
6,
7,
8
General introductions to the book on Painting.
9,
10,
11,
12,
13
The plan of the book on Painting.
14,
15,
16,
17
The use of the book on Painting.
18
Necessity of theoretical knowledge.
19,
20
The function of the eye.
21,
22,
23,
24
Variability of the eye.
25
Differences of perception by one eye and by both eyes.
26,
27,
28,
29
The comparative size of the image depends on the amount of light.
30,
31,
32,
33,
34,
35,
36,
37,
38,
39
. . .