Complete ignorance with regard to certain matters is perhaps the best thing for children; but let them learn very early what it is impossible to conceal from them permanently. Either their curiosity must never be aroused, or it must be satisfied before the age when it becomes a source of danger. Your conduct towards your pupil in this respect depends greatly on his individual circumstances, the society in which he moves, the position in which he may find himself, etc. Nothing must be left to chance; and if you are not sure of keeping him in ignorance of the difference between the sexes till he is sixteen, take care you teach him before he is ten. I do not like people to be too fastidious in speaking with children, nor should they go out of their way to avoid calling a spade a spade; they are always found out if they do. Good manners in this respect are always perfectly simple; but an imagination soiled by vice makes the ear over-sensitive and compels us to be constantly refining our expressions. Plain words do not matter; it is lascivious ideas which must be avoided. Although modesty is natural to man, it is not natural to children. Modesty only begins with the knowledge of evil; and how should children without this knowledge of evil have the feeling which results from it? To give them lessons in modesty and good conduct is to teach them that there are things shameful and wicked, and to give them a secret wish to know what these things are. Sooner or later they will find out, and the first spark which touches the imagination will certainly hasten the awakening of the senses. Blushes are the sign of guilt; true innocence is ashamed of nothing. Children have not the same desires as men; but they are subject like them to the same disagreeable needs which offend the senses, and by this means they may receive the same lessons in propriety. Follow the mind of nature which has located in the same place the organs of secret pleasures and those of disgusting needs; she teaches us the same precautions at different ages, sometimes by means of one idea and sometimes by another; to the man through modesty, to the child through cleanliness.