流产

莫衷一是

传统上，有关生死攸关问题的道德准则由各种既定的宗教和哲学体系予以诠释。可是，所诠释的观点并不始终如一。更有甚者，某些宗教和哲学体系既反对流产也反对避孕。依许多旁观者来看，这似乎不合逻辑。当代某些宗教团体在某种情况下和对早期妊娠流产持支持态度，而其他的宗教团体则不分皂白地反对流产，把每一次流产看作一次谋杀（为了救助孕妇的生命除外，这种案例是正当防卫）。一些教堂主张“从受精那一瞬间”一个胚胎就是一个生命。可是，科学家们不同意应该推测这样的特殊瞬间在什么时候发生和是否发生。在某种程度上，这是一个定义的问题。按科学的原理来说，人类的怀孕最好不要被描述成一个忽然的事件，而是要认定为一个逐渐的、复杂的过程；这个过程开始于卵子与精子的融合，并由此经历受精卵的各个分裂时期，最后生长中的胚泡植入子宫内膜。这个过程决不是自动的，它依许多不会始终存在的相关特殊条件而定。从某种程度上说，这个过程的演变将发生全然不同的转化，如果没有（胚泡）植入过程发生，受精卵只会分解。因此，按照一般的医学惯例，我们不用怀孕（conception）来表达，而是说：直到植入子宫内膜后，妊娠才开始发生。

Abortion

Differing Views

Moral guidance in life-and-death matters has traditionally been offered by the various established religions and philosophies. However, their views are not always identical. Moreover, some of them oppose both abortion and contraception. This seems illogical to many outside observers. Some contemporary religious groups favor abortions under certain circumstances and early in the pregnancy, while others are unconditionally opposed to them, considering every abortion to be murder (except to save the life of the mother, in which case it would be self-defense). Some churches maintain that an embryo is a human life "from the moment of conception." However, scientists do not agree as to whether and when such a particular moment should be presumed to occur. In a way, it is a matter of definition. Scientifically speaking, the conception of a human being is best described not as a sudden occurrence but as a gradual, complicated process which begins with the union of an egg and a sperm cell and leads through various stages to the eventual attachment of a growing cell cluster to the uterine wall. This process is by no means automatic. It depends on a number of interrelated special conditions which are not always present. In some cases, the development takes an entirely different turn, no implantation occurs, and the fertilized egg simply degenerates. Consequently, according to general medical usage, we do not speak of a conception, i.e. the beginning of pregnancy until the implantation in the uterus has taken place.