To misunderstand conscience is to risk great harm to oneself and others. There is a real need to understand
conscience correctly in order to help clarify the principles of right and wrong and explain why we should
follow them.
In Romans 2, 12–16 St Paul explains that even non-believers have the Law ‘written in their hearts … in
their consciences’. But what is ‘written in the heart’ is easily confused with ‘what is passionately felt or
wanted by the heart’, thus conscience can be subtly replaced with an appeal to whatever one most prefers
or strongly feels to be right.
To counteract this we should bear in mind that conscience is applying knowledge to human choices,

it is a way of thinking intelligently about what we have done and what we may do. Knowledge in turn always concerns what we have good reason for believing to be true: we do not have knowledge whenever we can parrot a truth but only when we have good reason for believing that truth. So conscience requires familiarity with truths about our choices and not just strong preferences for choosing one way or another.

Our individual experiences of conscience usually begin with a sense of freedom and of responsibility.
These always come together in good moral thinking. Someone who thinks ‘I’m free, I’m my own boss’ is
not experiencing conscience, and neither is someone who thinks ‘God’s my only boss, I have no say’.
Rather, to paraphrase Vatican Council II’s Gaudium et Spes: the experience of conscience is that of being alone in our choices with God; the stirrings of conscience make us face up to the truly awesome precepts of his law. What I am calling ‘the experience’ of conscience, however, is actually a number of discrete experiences which can occur consecutively or at quite different times. We can present them as three levels or operations of conscience:

1 What the Fathers and Scholastics called ‘synderesis’: recognising that certain types of action are
worth doing just because of what they are, independently of any desires they might satisfy or states
of affairs they might contribute towards bringing about. For example, we recognise the
worthwhileness of acts designed to secure the safety or health of some human being (including
ourselves), or acts of understanding some truth as opposed to remaining in ignorance or superstition,
or achieving social peace and counteracting disruption, or consolidating a real friendship not an
exploitative or purely sensual liaison, or giving honour to God and not practising idolatry or
blasphemy. At this first level of conscience we understand all such acts are worth doing because we
grasp that for beings such as us the objectives at stake – health, truth, justice, integrity, worship etc.
– are always good. The Church teaches that all human beings with the use of reason have this basic
and very general experience of conscience, and that it is infallible: our thoughts here can be relied
upon, unless our minds are seriously affected by disease or disorder.
However, consider this: if I know acting to restore my child’s health is a good thing but I believe
that the best available means of doing this involves lying, stealing, defrauding, injuring or
blaspheming and I am actively considering these, I do know something about conscience but not yet
the whole story. I do not yet have moral conscience.

2 To make morally good decisions in conscience we need to undertake some further reasoning about
these obviously choiceworthy acts. For this we need some specific moral principles, some good
habits (or ‘virtues’), the guidance of a sound community, moral exemplars, self control etc. In other
words, what we need is that our consciences be ‘well-formed’ so that we are more fully morally
aware. At this level conscience is not infallible: our formation may be defective, or we may apply
what we have learned wrongly (in genuine mistakes, negligently, or intentionally and wickedly).
This is the level of conscience of which we are generally most aware: we experience here the great
dilemmas and deliberations of our lives, the clashes of moral principles we must resolve as we
mature through rational thinking, prayer, and with the help and support of others.
But conscience would be of little use if we simply went on deliberating, studying moral philosophy,
thinking and praying endlessly. Sometimes at least, our thinking comes to an end and, however
difficult it is, we make a decision and act.

3 Decision-making is the final experience of conscience (the one the medievals called ‘conscientia’):
we judge that a particular act must be (may be, may not be, should have been, should not have
been) done. This ‘enactment’ of conscience is again fallible: we may make a wrong decision
through genuine ignorance or through some emotional confusion. But if we sincerely believe our
deliberation indicates it is appropriate (not) to perform some choiceworthy type of act [from
level 1] which has been shown to be morally permissible [from level 2], then we may act (and
perhaps, must act).
This 3-level model represents the basic position of Catholic thought on these matters since St
Thomas Aquinas and culminating in the twentieth century with Gaudium et Spes 16, the Catechism
of the Catholic Church 1780, and Pope John Paul II’s Encyclical Veritatis Splendor 54–64.
Conscience in Catholic tradition is our awareness of natural law and moral teaching, not an
alternative to these.
There is another aspect of conscience we need to consider. Vatican II’s Dignitatis Humanae 3 calls
conscience ‘the highest norm of human life’ and reminds us that it is always to be respected. What
does this mean? Certainly, we cannot force people to act against conscience or restrain them from
acting on conscience; that would be to force them to do what they believe to be wrong. We have to
recall, however, that respecting conscience – respecting an individual’s knowledge of moral law –
has little to do with respecting her strongest wishes or dearest opinions. There is no reason why we
should respect someone’s choice just because it is for something he dearly wants (we may
sympathise with him but that is a different thing from respecting his choice). Our dearest wants, we
well know, are often contradicted by conscience. Our strongest wish and firmest opinion ought to
be to go with well-formed conscience, not that conscience is bent so that it goes with our wishes
and opinions.

We bear special responsibility for conscience’s second level – its moral formation. Vatican II,
Dignitatis Humanae 14; also, Lumen Gentium 25 advises us here to attend above all to Church
teaching: the Church is the voice of Christ who is Truth, and since conscience is recognition and
service of truth, assent to Church teaching is required for good conscience, the sort of conscience
others can respect.
Nevertheless, awareness of Church teaching is not enough to form a conscience well. We also need
the capacity for self-criticism (constant self-examination, openness to all sources of truth, however
unwelcome, self-knowledge concerning the possibilities of emotional confusion); cultivation of
moral virtues (and so awareness too of the various vices of action and thought); attentiveness to emotional experiences of guilt, shame and remorse in doing evil (and joy, pride and delight in doing
good). Also, we need to recognise we are subject to (and certainly not always culpable for) our own
weaknesses and the state of our moral education. This should manifest itself as willingness to
question even our firmest views, the formal instruction we have had, our informal, social formation,
and the norms and models our society proposes.

But what can I do when my conscience is troubled, when perhaps I have already done a great deal
to resolve some moral confusion and now feel more confused than ever? First, I should get some
sleep, some food, exercise and fresh air: moral reasoning should not be a torment and when it is, we
may need temporary relief from it. Then we should recall that God never asks more of us than is
possible – but that under grace, much more is possible than we might at first think. We should of
course take the best advice, humbly accept the best moral authorities, pray to the Holy Spirit and
receive the sacraments. At this late stage of decision making we should still too be open to
challenges and to the need for conversion of heart.

If we have done all this and are still in doubt, then we can look again at the situation (am I ignoring
some morally relevant facts? am I considering any immoral options? are there any permissible
‘ways out’ I haven’t noticed?); at our goals (Do I know what my real purpose is? Am I actually
pursuing incompatible goals? is my purpose compatible with my longer-term goals and life-plan?);
and our motives (am I being driven by emotional factors that are likely to be harmful to me or
others?) Then ask: what would the very best human beings and those wisest in the area of my
dilemma do? What would Christ and the saints do? After this, we can do nothing more except seek
comfort and peace from others, then pray, spend some time in silence, trust and act.
What of someone who in evident sincerity says he does not accept Catholic faith or philosophy and
that his conscience instructs him to participate in killing children doomed to miserable or pain-filled
lives, or to carry out torture on behalf of an extreme régime, or, like Franz Stengl, commandant of
Treblinka death camp who said ‘never once did I act against my conscience’, to execute Jews?
Catholics believe that conscience is a different thing from sincerity or ‘conscientiousness’. The great
German philosopher Hegel agreed with Christ on some things, including this: absolute perversion
of conscience occurs when good choices appear to a sincere person as evils and evil choices as
goods. It is quite possible for people to become sincerely convinced that atrocities are right; but if
they then go on to take seriously this notion of rightness, they will see that if, for example, torture
is right, all sorts of other moral principles they rely upon must be wrong. If torture is permissible,
then perversion of truth – systematic deception – is also permissible (if protection of ideology
warrants torture, it certainly warrants lies); and if it is right to deceive people, to treat them as subrational, it must also be right to coerce and abuse them. Thus we cannot introduce a principle of
abortion or torture and hope to leave the rest of morality intact and uncorrupted: immorality infects
the whole system and will do so if we attempt to justify it by means of a ‘sincere conscience’. Not
even a regime of cowards or a pack of thieves can survive, and sustain their activities, with the whole
moral system tottering.

The only alternative to conscience understood as private wish and opinion or private sincerity is
conscience as the word itself implies: knowledge of and commitment to objective morality.