I. The Right to Life
It is a fundamental principle of most moral theories that all human beings have a right to life. The existence of a right implies obligations or duties of third parties towards right-holder. One has a right AGAINST other people. The fact that one possesses a certain right - prescribes to others certain obligatory behaviours and proscribes certain acts or omissions. This Janus-like nature of rights and duties as two sides of same ethical coin - creates great confusion. People often and easily confuse rights and their attendant duties or obligations with morally decent, or even with morally permissible. What one MUST do as a result of another's right - should never be confused with one SHOULD or OUGHT to do morally (in absence of a right).
The right to life has eight distinct strains:
IA. The right to be brought to life
IB. The right to be born
IC. The right to have one's life maintained
ID. The right not to be killed
IE. The right to have one's life saved
IF. The right to save one's life (erroneously limited to right to self-defence)
IG. The Right to terminate one's life
IH. The right to have one's life terminated
IA. The Right to be Brought to Life
Only living people have rights. There is a debate whether an egg is a living person - but there can be no doubt that it exists. Its rights - whatever they are - derive from fact that it exists and that it has potential to develop life. The right to be brought to life (the right to become or to be) pertains to a yet non-alive entity and, therefore, is null and void. Had this right existed, it would have implied an obligation or duty to give life to unborn and not yet conceived. No such duty or obligation exist.
IB. The Right to be Born
The right to be born crystallizes at moment of voluntary and intentional fertilization. If a woman knowingly engages in sexual intercourse for explicit and express purpose of having a child - then resulting fertilized egg has a right to mature and be born. Furthermore, born child has all rights a child has against his parents: food, shelter, emotional nourishment, education, and so on.
It is debatable whether such rights of fetus and, later, of child, exist if fertilization was either involuntary (rape) or unintentional ("accidental" pregnancies). It would seem that fetus has a right to be kept alive outside mother's womb, if possible. But it is not clear whether it has a right to go on using mother's body, or resources, or to burden her in any way in order to sustain its own life (see IC below).
IC. The Right to have One's Life Maintained
Does one have right to maintain one's life and prolong them at other people's expense? Does one have right to use other people's bodies, their property, their time, their resources and to deprive them of pleasure, comfort, material possessions, income, or any other thing?