"In relation to physical, economic, psychological and social conditions, responsible parenthood is exercised, either by the deliberate and generous decision to raise a numerous family, or by the decision, made for grave motives and with due respect for the moral law, to avoid for the time being, or even for an indeterminate period, a new birth. Responsible parenthood also and above all implies a more profound relationship to the objective moral order established by God, of which a right conscience is the faithful interpreter. The responsible exercise of parenthood implies, therefore, that husband and wife recognize fully their own duties towards God, towards themselves, towards the family and towards society, in a correct hierarchy of values. In the task of transmitting life, therefore, they are not free to proceed completely at will, as if they could determine in a wholly autonomous way the honest path to follow; but they must conform their activity to the creative intention of God, expressed in the very nature of marriage and of its acts, and manifested by the constant teaching of the Church."