It was developed by Immmnuel Kant in his works about Ethics where he creates the idea of categorical imperatives to prove the existence of God. This argument, however, is critized by those who don't believe in God and/or in an objective morality. Atheists & Agnostics argue morality is just result of evolution, necessity to follow rules or laws for survival. This argument is well presented by Professor Richard Dawkins in his latest documentary sex, death and the meaning of life, watch clicking in the link. As the documentary presents and some critics of the argument say, those moral choices derives from our own judgement using our conscience. This conscience is not guided by a transcendental source i.e. God but by our own instincts (or reason). Those "guilt feelings" are not given by God but produced inside on our own minds as a result of going against the moral rules established by society. Guilt feelings are caused by the conflicts between people's desires and the controlling influences of society, religion and/or family. This idea was developed by Sigmund Freud, the "founder" of psychoanalysis. Critics of Kantian argument, for example, Friedrich Nietzsche, in his works on Morality and Ethics, as in Ecce Homo, Beyond Good and Evil and Genealogy of Morals Nietzsche attack theidea of categorical imperatives since it is wrong and impossible to generalise/universalise morality, it varies from culture/society, changes in time and space.