The notion that forms the logic of contemporary moral discourse in the West is the notion of rights. It is important to note that, at present, we have more rights than we really know how to handle. We have smokers' rights, non-smokers' rights, the right to life, the right to choose, the right of consent, patients' rights, consumers' rights, marital rights' rights of the unborn, women's rights, employers' rights, employees' right, animal rights, and the most significant of all unalienable rights (thanks to Michael for the correction).
In order to understand what is going on in reference to the plethora of rights we have, while having no criteria by which to judge what actually is a right, we must first grapple with the Enlightenment project of embracing a universal morality that everyone can follow regardless of creed. This could be accomplished by constructing a moral system based upon the general principles that all religions supposedly have in common, while dispensing with the particular and unique doctrines of each religion.
Enlightenment philosophers believed that particular faith convictions stood in the way of a universal ethic. Those particular convictions, it is true, had caused more than their fair share of violence and bloodshed. This criticism was clearly beyond refutation. People were burned at the stake for their denial of the Trinity. Others were drowned because they rejected the practice of infant baptism. It is clearly understandable that many had a sour taste for the church's theology. Coupled with the growing belief in a closed universe, where the miraculous accounts in the Bible were now suspect, a crisis of authority, which began in embryonic form during the Protestant Reformation, now turned into a choir of philosophers extolling the primacy of reason in place of what Thomas Jefferson referred to as "superstition." Reason was now authoritative and even depicted in the form of a goddess. Human beings seem incurably religious; even a human faculty must be depicted in divine form.
In an attempt to fix the problem, the philosophers of the Enlightenment embarked on a two-fold repair project: First, deny the significance of doctrine for moral reflection, and second, take theological convictions out of the public realm making them nothing more than private individual preferences.