The Congregation for the Doctrine of the Faith has been approached by various Episcopal Conferences or individual Bishops, by theologians, doctors and scientists, concerning biomedical techniques which make it possible to intervene in the initial phase of the life of a human being and in the very processes of procreation and their conformity with the principles of Catholic morality. The present Instruction, which is the result of wide consultation and in particular of a careful evaluation of the declarations made by Episcopates, does not intend to repeat all the Church's teaching on the dignity of human life as it originates and on procreation, but to offer, in the light of the previous teaching of the Magisterium, some specific replies to the main questions being asked in this regard.
The exposition is arranged as follows: an introduction will recall the fundamental principles, of an anthropological and moral character, which are necessary for a proper evaluation of the problems and for working out replies to those questions; the first part will have as its subject respect for the human being from the first moment of his or her existence; the second part will deal with the moral questions raised by technical interventions on human procreation; the third part will offer some orientations on the relationships between moral law and civil law in terms of the respect due to human embryos and fetuses* and as regards the legitimacy of techniques of artificial procreation.
*The terms "zygote," "pre-embryo," "embryo" and "fetus" can indicate in the vocabulary of biology successive stages of the development of a human being. The present Instruction makes free use of these terms, attributing to them an identical ethical relevance, in order to designate the birth (whether visible or not) of human generation, from the first moment of its existence until birth. The reason for this usage is clarified by the text (cf I, 1).