The actual question posed was as follows:
After informing one's conscience, via the Church’s teaching, can a person go against what is taught by the Church, if his or her conscience is certain and informed and subsequently have no sin, even if there is grave matter involved?

To be brief, the problem lies in what one understands to be "an informed conscience", a term I find to be rather misleading, even when properly used. It tends to imply that all the Church offers is information, one opinion among others, which may be rejected, once one has examined the teaching and found it wanting. The Church's teaching is thus misunderstood just as one opinion among others, which, indeed, one should know about, but then can reject, if one does not agree with it. As a result, a person can then justify anything.

A similar misunderstanding is to conceive conscience as the intellectual judgement one must make on the reasons the Church gives for one or other aspect of the Church's moral teaching. If the reasons are unconvincing, it is argued, then one can reject them. In fact, one concludes that what the Church teaches to be wrong is in fact right, at least right for me.

To be a Catholic involves accepting that the Church cannot teach what is wrong in itself. We accept that the Church is guided by the Holy Spirit to teach what is right and wrong – what is pleasing to God or not – so as to enable us to flourish as human beings, to reach union with God, and to attain true happiness. The tradition of the Church, for example, has consistently condemned certain acts as objectively wrong – acts that a Christian should not even contemplate.

The theology of the Church's moral teaching is rich and complex. Some familiarity with the theology gives some kind of an insight (however inadequate) into why the Church so teaches – but only to those who already accept the Church's teaching or who are at least open to its truth. (With regard to the latter kind, people of ‘goodwill’, I am reminded of a Lutheran theologian and a Hindu scholar I once met on two different occasions who accepted the Church’s teaching on sexual ethics that many Catholics reject.)

In a word, the obedience of faith (the virtue of faith) includes submission to the Church's teaching authority on faith and morals, irrespective of how little we understand of the reasons why the Church so teaches. With regard to basic moral teaching, common sense – i.e. the human reason of a person of integrity and character, irrespective of their religious or cultural background – generally tells you what is right and wrong. (This is what we mean by natural law). However, one's good sense can be undermined or made uncertain by misconceptions that gain currency in the dominant culture one finds oneself in, as is the case in the so-called advanced societies of the Western world of today.

Good sense can also be too vague to be useful with regard to more refined acts or new moral dilemmas, as in bioethics. In these cases, the Church's teaching has a prophetic role. It confirms the truth that people of integrity in every society have recognised as right or wrong and it clarifies what may be clouded by one’s culture. For a Catholic, one submits to what the Church teaches and uses it as a guide. One trusts the Church’s teaching authority.
Conscience is the prudential judgement as to what one should do in a particular situation while adhering to that "common sense", which is confirmed and/or clarified by the Church's moral teaching. It does not mean choosing which of the moral principles one accepts or which one suits one's particular situation.

For a Catholic to act against the clear teaching of the Church, once one knows what that teaching is, is to sin.

In conclusion, we might remember the insight of the great Lutheran philosopher, Kierkegaard into the human heart as found in his Sickness unto Death. “Most people”, he observed, “work gradually at eclipsing their ethical and ethical-religious comprehension.” He believed that moral knowledge is universally distributed, in the form of conscience. However, as he saw it, conscience has an uphill battle because we all know in our bones that its directives will clash with what seems to be our immediate self-interest.

So what do we do when our moral principles push us towards losing our jobs or our friends, or just having to put up with people's irritation with us? He answers, “We allow a little time to elapse, an interim called: 'We shall look at it tomorrow.'" And during that interval our moral knowledge becomes more and more obscured, until finally we come to our senses and convince ourselves that the convenient course is the righteous course.”* A falsely understood ‘informed conscience’ can be the ‘Catholic’ way of convincing ourselves that what we have chosen to do is the righteous course.

*Gordon Marion: http://chronicle.com/free/v50/i24/24b00501.htm

D. Vincent Twomey, SVD, is the author of Benedict XVI: The Conscience of Our Age, (Ignatius Press 2007) and The End of Irish Catholicism? (Veritas 2003).

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