There is no mystery about this choice; its rules are well known, but I think we ought probably to pay more attention to the age of the milk as well as its quality. The first milk is watery, it must be almost an aperient, to purge the remains of the meconium curdled in the bowels of the new-born child. Little by little the milk thickens and supplies more solid food as the child is able to digest it. It is surely not without cause that nature changes the milk in the female of every species according to the age of the offspring. Thus a new-born child requires a nurse who has recently become mother. There is, I know, a difficulty here, but as soon as we leave the path of nature there are difficulties in the way of all well-doing. The wrong course is the only right one under the circumstances, so we take it. The nurse must be healthy alike in disposition and in body. The violence of the passions as well as the humours may spoil her milk. Moreover, to consider the body only is to keep only half our aim in view. The milk may be good and the nurse bad; a good character is as necessary as a good constitution. If you choose a vicious person, I do not say her foster-child will acquire her vices, but he will suffer for them. Ought she not to bestow on him day by day, along with her milk, a care which calls for zeal, patience, gentleness, and cleanliness. If she is intemperate and greedy her milk will soon be spoilt; if she is careless and hasty what will become of a poor little wretch left to her mercy, and unable either to protect himself or to complain. The wicked are never good for anything. The choice is all the more important because her foster-child should have no other guardian, just as he should have no teacher but his tutor. This was the custom of the ancients, who talked less but acted more wisely than we. The nurse never left her foster-daughter; this is why the nurse is the confidante in most of their plays. A child who passes through many hands in turn, can never be well brought up. At every change he makes a secret comparison, which continually tends to lessen his respect for those who control him, and with it their authority over him. If once he thinks there are grown-up people with no more sense than children the authority of age is destroyed and his education is ruined. A child should know no betters but its father and mother, or failing them its foster-mother and its tutor, and even this is one too many, but this division is inevitable, and the best that can be done in the way of remedy is that the man and woman who control him shall be so well agreed with regard to him that they seem like one. The nurse must live rather more comfortably, she must have rather more substantial food, but her whole way of living must not be altered, for a sudden change, even a change for the better, is dangerous to health, and since her usual way of life has made her healthy and strong, why change it?