E/CN.4/2000/65 page 42 ministerial priesthood, this in no way detracts from the role of women, or for that matter from the role of the other members of the Church who are not ordained to the sacred ministry, since all share equally in the dignity proper to the ‘common priesthood’ based on Baptism. These role distinctions should not be viewed in accordance with the criteria of functionality typical in human societies. Rather they must be understood according to the particular criteria of the sacramental economy, i.e. the economy of ‘signs’ which God freely chooses in order to become present in the midst of humanity.” 158. In the 1976 Declaration on the question of the admission of women to the priesthood, it is explained that the priesthood should in no way be considered as a right: baptism confers no personal entitlement to the ministerial function in the Church. The priesthood is never conferred for the honour or benefit of the person receiving it, but as a service to God and the Church. It is based on an explicit and totally selfless vocation. “It was not you who chose me; it was I who chose and instituted you” … Equality is not the same as identity, and in this sense the Church is a differentiated body, in which each individual plays a role; the roles are different and should not be confused, but they do not give rise to any superiority of some over others. 2. Procreation and abortion 159. With regard to the procreation aspect of women and the family, the Vatican has expressed views on the question of genetic action, the regulation of fertility and medically assisted reproduction. It has also taken a position on abortion. (a) Genetic action 160. A distinction needs to be drawn in this respect between strictly therapeutic action, aimed at treating illness due to genetic or chromosomal anomalies (which is generally speaking desirable, provided that it tends genuinely to promote the personal well-being of the individual without impairing his or her integrity or adversely affecting his or her living conditions), and manipulation altering the genetic heritage of human embryos (aimed at producing human beings pre-selected according to sex or other chosen characteristics, which would be contrary to personal dignity and to the interests of the human species). (b) Fertility control 161. The Vatican considers that it is legitimate, on serious grounds, to make use of knowledge of female fertility and to forego marital prerogatives during fertile periods, but that it is illegitimate to resort to contraceptive methods. According to the Holy See, natural methods include accepting a person’s time, in this case the female cycle, but also accepting dialogue, mutual respect and joint responsibility. Artificial means, on the other hand, introduce a split between sexual relations and procreation and submit fertility to arbitrary decisions by men and women. (c) Medically assisted procreation 162. Any medical means of intervention used to further procreation must take the form of assistance, but must never substitute for the conjugal act. Thus the Vatican does not necessarily