And in this especially a man ought to be subject to the chief and master of the Art.

And there are things in which Art is the instrument of Nature, and these are lesser Arts; and in these the artificers are less subject to their chief, as in giving the seed to the Earth, where one must await the will of Nature; as to sail out of the harbour or port, where one must await the natural disposition of the weather; and therefore we often see in these things contention amongst the artificers, and the greater to ask counsel of the lesser.
And there are other things which are not Arts, but appear to have some relationship with them; and therefore men are often deceived; and in these the scholars are not subject to a master, neither are they bound to believe in him so far as regards the Art.

Thus, to fish seems to have some relationship with navigation; and to know the virtue of the herb or grass seems to have some relationship with agriculture; for these Arts have no general rule, since fishing may be below the Art of hunting, and beneath its command; to know the virtue of the herb may be below the science of medicine, or rather below its most noble teaching.
Those things which have been argued concerning the other Arts in like manner may be seen in the Imperial Art, for there are rules in those Arts which are pure or simple Arts, as are the laws of marriage, of servants, of armies, of successors in offices of dignity; and in all these we may be entirely subject to the Emperor without doubt and without any suspicion whatever.

There are other laws which are the followers of Nature, such as to constitute a man of sufficient age to fill some office in the administration; and to such a law as this we are entirely subject; there are many others which appear to have some relationship with the Imperial Art; and here he was and is deceived who believes that the Imperial judgment in this part may be authentic, as of youth, whose nature is laid down by no Imperial judgment, as it were, of the Emperor.

Render, therefore, unto God that which is God's.
Wherefore it is not to be believed, nor to be allowed, because it was said by Nero the Emperor that youth is beauty and strength of body; but credit would be given to the philosopher who should say that youth is the crown or summit of the natural life.