I ask: which of the two, civil or natural life, is more likely to become insufferable to those who live it? We see about us practically no people who… - Jean-Jacques Rousseau

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.

There is, I feel, an age at which the individual man would want to stop: you will seek the age at which you would desire your Species had stopped. Discontented with your present state for reasons that foretell even greater discontents for your unhappy Posterity, perhaps you would want to be able to go backward in time. This sentiment must be the Eulogy of your first ancestors, the criticism of your contemporaries, and the dread of those who will have the unhappiness to live after you.

It makes me feel very much what I believe I have said in some work, that remorse sleeps during a prosperous fate and grows sour in adversity