M. Vitruvius per Iocundum solito castigatior factus cum figuris et tabula ut iam legi et intelligi possit

...such as Miron or Polycletus, but not ignorant of the sculptor's art: nor again a physician such as Hippocrates, but not ignorant of medical theory: nor singularly excelling in the other doctrines, but not unskilled in them. For in such varieties of things, no one can achieve singular elegances, as it barely falls into the power of anyone to know and perceive the reasonings of them. Nor indeed do architects not only fail to have the highest effect in all things, but even they themselves who privately hold the properties of the arts do not ensure that they have the highest primacy of praise. Therefore, if in individual doctrines individual artists, and not all, but a few in the perpetual age have barely achieved nobility, how can an architect, who must be skilled in many arts, not do the same wonderful and great thing, and not need them, but also excel all artists who have stood out in individual doctrines with assiduity and highest industry? Therefore, in this matter, Pythius seems to have erred, because he did not observe that individual arts are composed from two things: from work and its reasoning. Of these, however, one is proper to those who are exercised in individual things, that is, the effect of the work; the other is common to all the learned, that is, reasoning: such as for physicians and musicians, about the rhythmic and the movement of feet. But if it is necessary to heal a wound or snatch a sick man from danger, the musician will not approach, but that work will be proper to the physician. Likewise, in the organ, not the physician but the musician will modulate, so that the ears may receive pleasure from the songs. Similarly, with astrologers and musicians, there is a common dispute about the sympathy of the stars and symphonies, in squares, and triangles, the fourth, and the fifth: with geometers about vision, which is called in Greek logos optikos optical theory: and with all other doctrines, many things, or all, are common only for disputing. The beginning of works, however, which are brought to elegance by hand and handling, are of those who are properly instructed by one art to do them. Therefore, he seems to have done enough who has the parts and reasonings of individual doctrines moderately known, and those which are necessary for architecture: so that if there should be a need to judge and approve work about these things and arts, he may not fail. Those to whom nature has indeed granted such skill, acuteness, and memory that they can have geometry, astrology, music, and other disciplines thoroughly known, pass beyond the duties of an architect and become mathematicians. Therefore, they can easily dispute against those disciplines, because they are armed with many weapons of the disciplines. These, however, are found rarely, as there once were Aristarchus of Samos, Philolaus and Archytas of Tarentum, Apollonius of Perga, Eratosthenes of Cyrene, Archimedes, and Scopinas of Syracuse, who left to posterity many organic and gnomonic things, found and explained by number and natural reasonings. Since, therefore, such talents are granted not to all nations everywhere, but to a few men by natural skill, and the duty of an architect must be exercised in all eruditions, and the matter because of the scale of the thing permits having not the highest, but the moderate sciences of the disciplines, I ask, Caesar, and from you, and from those who are to read my volumes, that if anything is a little...