Food does no good and is not assimilated into the body if it leaves the stomach as soon as it is eaten; nothing hinders a cure so much as frequent change of medicine; no wound will heal when one salve is tried after another; a plant which is often moved can never grow strong. There is nothing so efficacious that it can be helpful while it is being shifted about. And in reading of many books is distraction. Accordingly, since you cannot read all the books which you may possess, it is enough to possess only as many books as you can read.