into them a spirit so strong and of such skilful contrivance as to reach a long way and to fashion the forms of things which are seen?  What messenger is so swift and vigilant?  And to no purpose has he made the interjacent atmosphere so efficacious and elastic that the vision penetrates through the atmosphere which is in a manner moved?  And to no purpose has he made light, without the presence of which there would be no use in any other thing?

Man, be neither ungrateful for these gifts nor yet forget the things which are superior to them.  But indeed for the power of seeing and hearing, and indeed for life itself, and for the things which contribute to support it, for the fruits which are dry, and for wine and oil give thanks to God:  but remember that he has given you something else better than all these, I mean the power of using them, proving them, and estimating the value of each.  For what is that which gives information about each of these powers, what each of them is worth?  Is it each faculty itself?  Did you ever hear the faculty of vision saying anything about itself? or the faculty of hearing? or wheat, or barley, or a horse, or a dog?  No; but they are appointed as ministers and slaves to serve the faculty which has the power of making use of the appearances of things.  And if you inquire what is the value of each thing, of whom do you inquire? who answers you?  How then can any other faculty be more powerful than this, which uses the rest as ministers and itself proves each and pronounces about them? for which of them knows what itself is, and what is its own value? which of them knows when it ought to employ itself and when not? what faculty is it which opens and closes the eyes, and turns them away from objects to which it ought not to apply them and does apply them to other objects?  Is it the faculty of vision?  No, but it is the faculty of the will.  What is that faculty which closes and opens the ears? what is that by which they are curious and inquisitive, or on the contrary unmoved by what is said? is it the faculty of hearing?  It is no other than the faculty of the will.  Will this faculty then, seeing that it is amidst all the other faculties which are blind and dumb and unable to see anything else except the very acts for which they are appointed in order to minister to this (faculty) and serve it, but this faculty alone sees sharp and sees what is the value of each of the rest; will this faculty declare to us that anything else is the best, or that itself is?  And what else does the eye do when it is opened than see?  But whether we ought to look on the wife of a certain person, and in what manner, who tells us?  The faculty of the will.  And whether we ought to believe what is said or not to believe it, and if we do believe, whether we ought to be moved by it or not, who tells us?  Is it not the faculty of the will?