When does human life begin?

The main purpose for debating the question concerning the time at which human life begins is finding a way of determining when if ever terminating the process of procreation is morally acceptable. For none or few would object to the destruction of a clump of cells which is clearly not a human being. But all or most would oppose the destruction of a being which is clearly human.

View 1: Human life begins at conception or syngamy, that is, when a sperm fertilizes the ovum.

View 2: Human life begins at implantation, that is, when the fertilized egg becomes implanted in the womb.

View 3: Human life begins at quickening, that is, the time when movements can be detected in the fetus.

View 4: Human life begins at viability, that is, the time when the fetus can be delivered and survive outside the body of its mother. The fetus has a chance of living on its own if it is delivered after the start of the third trimester. The abortion of a fetus in the last 12 weeks of a pregnancy, therefore, is the destruction of a potentially independent being.

Reply: Viability is to some extent dependent on technological capabilities. The availability of life-support equipment at the time of a premature delivery may determine whether the being which is delivered from the womb survives.

View 5: Human life begins at the time when brain waves begin to be observed.

Reply: The time when the observation of brain waves in the fetus becomes possible may not be the time when the brain waves actually begin. The techniques for making the observations or collecting the data may not be sufficiently refined to enable us to identify the precise moment when the brain in the fetus starts functioning.

View 6: Human life begins with the onset of integrated cerebral functioning (ICF).

View 7: Human life begins at birth.

Reply: There is little difference between a fetus at full term and a baby just born.