INTRODUCTION.

I know that many will call this useless work [Footnote: 3. questa
essere opera inutile. By opera we must here understand libro di
pittura and particularly the treatise on Perspective.]; and they
will be those of whom Demetrius [Footnote: 4. Demetrio. "With regard
to the passage attributed to Demetrius", Dr. H. MULLER STRUBING
writes, "I know not what to make of it. It is certainly not
Demetrius Phalereus that is meant and it can hardly be Demetrius
Poliorcetes. Who then can it be--for the name is a very common one?
It may be a clerical error for Demades and the maxim is quite in the
spirit of his writings I have not however been able to find any
corresponding passage either in the 'Fragments' (C. MULLER, _Orat.
Att._, II. 441) nor in the Supplements collected by DIETZ (_Rhein.
Mus._, vol. 29, p. 108)."

The same passage occurs as a simple Memorandum in the MS. Tr. 57,
apparently as a note for this '_Proemio_' thus affording some data
as to the time where these introductions were written.] declared
that he took no more account of the wind that came out their mouth
in words, than of that they expelled from their lower parts: men who
desire nothing but material riches and are absolutely devoid of that
of wisdom, which is the food and the only true riches of the mind.
For so much more worthy as the soul is than the body, so much more
noble are the possessions of the soul than those of the body. And
often, when I see one of these men take this work in his hand, I
wonder that he does not put it to his nose, like a monkey, or ask me
if it is something good to eat.

[Footnote: In the original, the Proemio di prospettiva cioe
dell'uffitio dell'occhio (see No. 21) stands between this and the
preceding one, No. 9.]

INTRODUCTION.

I am fully concious that, not being a literary man, certain
presumptuous persons will think that they may reasonably blame me;
alleging that I am not a man of letters. Foolish folks! do they not
know that I might retort as Marius did to the Roman Patricians
[Footnote 21: _Come Mario disse ai patriti Romani_. "I am unable to
find the words here attributed by Leonardo to Marius, either in
Plutarch's Life of Marius or in the Apophthegmata (_Moralia_,
p.202). Nor do they occur in the writings of Valerius Maximus (who
frequently mentions Marius) nor in Velleius Paterculus (II, 11 to
43), Dio Cassius, Aulus Gellius, or Macrobius. Professor E.
MENDELSON of Dorpat, the editor of Herodian, assures me that no such
passage is the found in that author" (communication from Dr. MULLER
STRUBING). Leonardo evidently meant to allude to some well known
incident in Roman history and the mention of Marius is the result
probably of some confusion. We may perhaps read, for Marius,
Menenius Agrippa, though in that case it is true we must alter
Patriti to Plebei. The change is a serious one. but it would render
the passage perfectly clear.] by saying: That they, who deck
themselves out in the labours of others will not allow me my own.
They will say that I, having no literary skill, cannot properly
express that which I desire to treat of [Footnote 26: _le mie cose
.... che d'altra parola_. This can hardly be reconciled with Mons.
RAVAISSON'S estimate of L. da Vinci's learning. "_Leonard de Vinci
etait un admirateur et un disciple des anciens, aussi bien dans
l'art que dans la science et il tenait a passer pour tel meme aux
yeux de la posterite._" _Gaz. des Beaux arts. Oct. 1877.]; but they
do not know that my subjects are to be dealt with by experience
rather than by words [Footnote 28: See Footnote 26]; and
[experience] has been the mistress of those who wrote well. And so,
as mistress, I will cite her in all cases.