XX. It is a mistake to imagine that slavery pervades a man's whole being; the better part of him is exempt from it: the body indeed is subjected and in the power of a master, but the mind is independent, and indeed is so free and wild, that it cannot be restrained even by this prison of the body, wherein it is confined, from following its own impulses, dealing with gigantic designs, and soaring into the infinite, accompanied by all the host of heaven. It is, therefore, only the body which misfortune hands over to a master, and which he buys and sells; this inward part cannot be transferred as a chattel. Whatever comes from this, is free; indeed, we are not allowed to order all things to be done, nor are slaves compelled to obey us in all things; they will not carry out treasonable orders, or lend their hands to an act of crime. XXI. There are some things which the law neither enjoins nor forbids; it is in these that a slave finds the means of bestowing benefits. As long as we only receive what is generally demanded from a slave, that is mere service; when more is given than a slave need afford us, it is a benefit; as soon as what he does begins to partake of the affection of a friend, it can no longer be called service. There are certain things with which a master is bound to provide his slave, such as food and clothing; no one calls this a benefit; but supposing that he indulges his slave, educates him above his station, teaches him arts which free-born men learn, that is a benefit. The converse is true in the case of the slave; anything which goes beyond the rules of a slave's duty, which is done of his own free will, and not in obedience to orders, is a benefit, provided it be of sufficient importance to be called by such a name if bestowed by any other person.