There is within the souls of man an innate principle of justice and virtue on the basis of which, against our own convictions, we judge our actions and others as good or bad, and this principle is consciousness…
 If this were the subject here, I would try to show how the first voices of consciousness appear from the heart of man, and how from the feeling of love and hatred are born the notion of good and bad.
I would like to show that justice and kidness are not just abstract words, pure moral creations made by thought, but true feelings of the soul enlightened by rationality, that they are an orderly progression of our primary feelings.
I would like to show that only by rationality, independent of consciousness, it is not possible to establish any natural law, and that the entire natural right is just a chimera if it is not based on a natural necessity of the human soul.
Even the precept of behaving towards one another in the way we want from the other to behave towards us is based on consciousness and sentiment. Someone may ask where is the exact reason to behave as if he were another, knowing that he would not, morally, ever be in this case; and if he follows this principle, will this cause others to do the same ?
The villain makes profit from his own injustice and the honor of right man, and it’s easy for him that everyone is honest, excepting him. This agreement, whatever it is said, is not very advantageous for the right people. If I were him, it means that in order not to feel pain, I don’t want him to feel pain. I’m interested in him for love for me, and the basis of the precept is in the nature itself, which inspires me the desire of my well-being anywhere i would be.
Hence, it results that is not true that the laws of human nature would be based only on rationality, having a safer and more solid base. Love for people, coming from self-love, is the principle of human justice.
J. J. Rousseau, Emil, or On Education