When you reached the age of reason, I secured you from the influence of human prejudice; when your heart awoke I preserved you from the sway of passion. Had I been able to prolong this inner tranquillity till your life's end, my work would have been secure, and you would have been as happy as man can be; but, my dear Emile, in vain did I dip you in the waters of Styx, I could not make you everywhere invulnerable; a fresh enemy has appeared, whom you have not yet learnt to conquer, and from whom I cannot save you. That enemy is yourself. Nature and fortune had left you free. You could face poverty, you could bear bodily pain; the sufferings of the heart were unknown to you; you were then dependent on nothing but your position as a human being; now you depend on all the ties you have formed for yourself; you have learnt to desire, and you are now the slave of your desires. Without any change in yourself, without any insult, any injury to yourself, what sorrows may attack your soul, what pains may you suffer without sickness, how many deaths may you die and yet live! A lie, an error, a suspicion, may plunge you in despair.
Jean-Jacques Rousseau