Socrates gives us a basic insight into the nature of teaching when he compares the art of teaching to the ancient craft of the midwife. Just as the midwife assists the body to give birth to new life, so the teacher assists the mind to deliver itself of ideas, knowledge, and understanding. The essential notion here is that teaching is a humble, helping art. The teacher does not produce knowledge or stuff ideas into an empty, passive mind. It is the learner, not the teacher, who is the active producer of knowledge and ideas.The ancients distinguish the skills of the physician and the farmer from those of the shoemaker and the house builder. Aristotle calls medicine and agriculture cooperative arts, because they work with nature to achieve results that nature is able to produce by itself. Shoes and houses would not exist unless men produced them; but the living body attains health without the intervention of doctors, and plants and animals grow without the aid of farmers. The skilled physician or farmer simply makes health or growth more certain and regular.Teaching, like farming and healing, is a cooperative art which helps nature do what it can do itself — though not as well without it. We have all learned many things without the aid of a teacher. Some exceptional individuals have acquired wide learning and deep insight with very little formal schooling. But for most of us the process of learning is made more certain and less painful when we have a teacher’s help.One basic aspect of teaching is not found in the other two cooperative arts that work with organic nature. Teaching always involves a relation between the mind of one person and the mind of another. The teacher is not merely a talking book, a living phonograph record, broadcast to an unknown audience. He enters into a dialogue with his student. This dialogue goes far beyond more “talk”, for a good deal of what is taught is transmitted almost unconsciously in the personal interchange between teacher and student. We might get by with encyclopedias, phonograph records, and TV broadcasts if it were not for this intangible element, which is present in every good teacher-student relation.Speaking simply and in the broadest sense, the teacher shows the student how to find out, evaluate, judge, and recognize the truth. He does not impose a fixed content of ideas and doctrines that the student must learn by rote. He teaches the student how to learn and think for himself. He encourages rather than suppresses a critical and intelligent response.The student’s response and growth is the only reward suitable for such a labor of love. Teaching, the highest of the cooperative arts, is devoted to the good of others. It is an act of supreme generosity. St. Augustine calls it the greatest act of charity.25. Why did St. Augustine call teaching the greatest act of charity?