III. (9) On this account he does not say that Sarah did not bring forth at all, but only that she did not bring forth for him, for Abraham. For we are not as yet capable of becoming the fathers of offspring of virtue, unless we first of all have a connection with her handmaiden; and the handmaiden of wisdom is the encyclical knowledge of music and logic, arrived at by previous instruction. (10) For as in houses there are vestibules placed in front of staircases, and as in cities there are suburbs, through which one must pass in order to enter into the cities; so also the encyclical branches of instruction are placed in front of virtue, for they are the road which conducts to her. (11) And as you must know that it is common for there to be great preludes to great propositions, and the greatest of all propositions is virtue, for it is conversant about the most important of all materials, namely, about the universal life of man; very naturally, therefore, that will not employ any short preface, but rather it will use as such, grammar, geometry, astronomy, rhetoric, music, and all the other sorts of contemplation which proceed in accordance with reason; of which Hagar, the handmaid of Sarah, is an emblem, as we will proceed to show. (12) “For Sarah,” says Moses, “said unto Abraham, Behold, the Lord has closed me up, so that I may not bear children. Go in unto my handmaiden, that thou mayest have children by her.” Now, we must take out of the present discussion those conjunctions and connections of body with body which have pleasure for their end. For this is the connection of the mind with virtue, which is desirous to have children by her, and which, if it cannot do so at once, is at all events taught to espouse her handmaid, namely, intermediate instruction.