not knowing what it is, or through not wishing to follow it—­the written Reason, the Law, was invented, both to point it out to us and to command its observance.  Wherefore Augustine says:  “If men could know this, that is, Equity, and knowing it would obey it, the written Reason, the Law, would not be needful.”  And therefore it is written in the beginning of the old Digests or Books of the Civil Law:  “The written Reason is the Art of Goodness and of Equity.”  To write this, to show forth and to enforce this, is the business of that Official Post of which one speaks, that of the Emperor, to whom, as has been said, in so far as our own operations extend, we are subject, and no farther.  For this reason in each Art and in each trade the artificers and the scholars are and ought to be subject to the chief and to the master of their trades and Art:  beyond their callings the subjection ceases, because the superiority ceases.  So that it is possible to speak of the Emperor in this manner, if we will represent his office figuratively, and say that he may be the rider of the Human Will, of which horse how it goes without its rider through the field is evident enough, and especially in miserable Italy, left without any means for its right government.  And it is to be considered that in proportion as a thing is more fit for the Master’s art, so much the greater is the subjection; for the cause being multiplied, so is the effect multiplied.  Wherefore it is to be known that there are things which are such pure or simple Arts that Nature is their instrument; even as rowing with an oar, where the Art makes its instrument by impulsion, which is a natural movement; as in the threshing of the corn, where the Art makes its instrument, which is a natural quality.  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.