Facts and doubts on the beginning of human life - scientific, legal, philosophical and religious controversies.

It is very complicated to give correct answer to the question "How to define human life?" Nowadays dilemmas consider the respect of human life from the birth to death involve not just biology but also other sciences like philosophy, theology, sociology, psychology, law and politics. These sciences evaluate the topic from different points of view. Integration of all of these perspectives could result with a proper definition. The principal purpose of this paper is to try to determine when a human individual begins. If this proves to be too difficult, we might have to settle for a specific stage in the reproductive process before which it would be impossible to say with any plausibility that a human individual exists. It is necessary to return the moral dimension of observation to the science of life. The point is to reconcile the universal ethical principles concerning the absolute value of life with the everyday challenges and dilemmas. It is our deepest conviction that life has an absolute value and that there always remains something indestructible and substantial in life, which may neither be evaluated by anything final, nor completely reduced to the material biological equivalent and the genetic substratum.