Pope John Paul II: “Contraception is to be judged objectively so profoundly illicit that it can never, for any reason, be justified. To think, or to say, anything to the contrary is tantamount to saying that in human life there can be situations where it is legitimate not to recognize God as God. Users of contraception attribute to themselves a power that belongs only to God, the power to decide in the final instance the coming into existence of a human being.” (Address on Responsible Procreation)
The Magisterium teaches that contraception can never be justified, not for any reason. Those persons who claim that contraception can be justified outside of marriage, to prevent a child from being conceived out of wedlock, are rejecting this magisterial teaching. Those persons who claim that contraception can be justified by the principle of double effect are rejecting this magisterial teaching. Those persons who claim that, when abortifacient contraception is used for a medical reason, it is permissible to choose to have contracepted sex, are rejecting this teaching. The holy Pontiff teaches, just as the Magisterium has taught many times, that contraception is NEVER justified. Those who say otherwise have rejected the infallible teaching of the ordinary and universal Magisterium. Those who teach otherwise are teaching heresy.
Contraception is called “profoundly illicit” because it is gravely immoral by the very nature of the chosen act, in and of itself. The moral nature (or moral species) of an act is its essential moral meaning; it is the inherent moral nature of the act — the very core of the act, in terms of morality, before the eyes of God. Nothing is more profound concerning human acts than the moral nature of the act, whether it is intrinsically evil or intrinsically good, by its very nature.
Those who think or say otherwise, are in effect saying that, in some circumstances, or with certain intentions, it would be legitimate “not to recognize God as God.” In other words, the choice of contraception is a rejection of the will and plan of God for human sexuality; such a choice treats the human will, its intentions and its choices in certain circumstances, as if it were the highest moral power. And yet this type of wickedness is currently widespread among persons who call themselves Catholics. And there is no shortage of Catholic teachers who have distorted the magisterial against contraception, so as to justify it with certain intentions or in certain circumstances.
The above text is an excerpt from my book:
Roman Catholic Teaching on Abortion and Contraception