Creation points back to its Creator. Just as something of the composer is revealed in his symphony and something of the artist is revealed in his painting, so also is God, in an indirect but real way, revealed in his divine handiwork. The revelatory clues found in nature tell us more than just the fact of God’s existence; they tell us also what kind of God the Creator is. Some of these clues lie right before our noses in the world around us, while others lie deep inside of us. Among these interior signs is the conscience, which points not merely toward the existence of God but the existence of a personal God.

In his Essay in Aid of a Grammar of Assent, St. John Henry Newman sets out to demonstrate how we come to assent to—or have faith in—the reality of God. Newman explores the evidential significance of the human conscience, suggesting how this mysterious interior faculty, and its presence and effect upon us, points toward the reality of a divine moral legislator. Newman writes in his Letter to the Duke of Norfolk:

Conscience is a law of the mind; yet [Christians] would not grant that it is nothing more. . . . [Conscience] is a messenger of him, who, both in nature and in grace, speaks to us behind a veil, and teaches and rules us by his representatives. Conscience is the aboriginal Vicar of Christ.

The question is: Where does our conscience come from?

The absolute authority of conscience

The Catechism of the Catholic Church tells us that conscience is “a judgment of reason by which the human person recognizes the moral quality of a concrete act.” It is a rational human faculty, agrees Newman, like memory, reason, and the sense of beauty; yet it also has a moral sovereignty over us. We often find ourselves going where we do not want to go, doing what we do not want to do, or saying what we do not want to say; our conscience informs us of this.

“There comes a time when one must take a position that is neither safe, nor politic, nor popular but he must take it because conscience tells him it is right,” affirmed Martin Luther King Jr. in his famous speech “A Proper Sense of Priorities.” Truly, the conscience demands unconditional obedience, respect, and loyalty—often at a cost. Yet to disobey our conscience is often the more immediately painful option, at least on an emotional level. Strangely, in a culture so averse to moral authorities, despite the potential consequences of choosing the right decision over the popular decision, almost no one would say it’s okay to disobey one’s conscience. It may not even be possible to say “It’s okay to disobey your conscience” without disobeying your conscience.

But where on earth does such firm and unshakable authority over humanity come from? Peter Kreeft writes:

Conscience has absolute, exceptionless, binding moral authority over us, demanding unqualified obedience. But only a perfectly good, righteous divine will has this authority and a right to absolute, exceptionless obedience. Therefore, conscience is the voice of the will of God.

Newman implies the same when he calls conscience the “aboriginal Vicar of Christ.” He, too, was in awe of the mysterious authority of the conscience and believed the best explanation behind it was a supreme and authoritative personal authority, which he characterizes powerfully in this reflection:

Man has within his breast a certain commanding dictate, not a mere sentiment, not a mere opinion or impression or view of things, but a law, an authoritative voice, bidding him do certain things and avoid others. . . . What I am insisting on here is this, that it commands; that it praises, blames, it threatens, it implies a future, and it witnesses of the unseen. It is more than a man’s own self. The man himself has no power over it, or only with extreme difficulty; he did not make it, he cannot destroy it.

Feelings and conscience

It is common—and mistaken—to equate feelings with conscience; they are not the same thing. Feelings (unless bridled according to right reason) are often fleeting, impulsive, and irrational. Conscience on the other hand is abiding, authoritative, and reasonable. These distinctions are key. As Kreeft points out, “If our immediate feelings were the voice of God, we would have to be polytheists or else God would have to be schizophrenic.” Feelings may accompany our conscience, but they are not synonymous with it.

Newman suggests that such a relationship between conscience and the feelings it potentially invokes only makes sense if there is a personal explanation behind it. He writes, “If, as is the case, we feel responsibility, are ashamed, are frightened, at transgressing the voice of the conscience, this implies that there is One to whom we are responsible, before whom we are ashamed, whose claim upon us we fear.”

Through our conscience we discern not only a moral law but a moral lawgiver. When we transgress our interior moral compass, we feel a genuine sense of guilt, as though we have let someone down. On the other hand, when we obey our conscience we feel invigorated—particularly if such obedience requires great courage—as though we have been praised by another. But merely clinical objects like brains neither praise nor blame. The experience of our conscience is distinctly relational and points to a personal being who is holding us accountable for our actions.

Where does conscience come from?

That there is no moral authority outside of oneself is a favorite assertion of our postmodern, post-Christian age. Yet despite this popular attitude, there is a common human experience of something akin to moral obligation. There does seem to be a “right way” to act, regardless of our personal views; there does seem to be an interior voice within us that commands us to do good always and to avoid evil.

Some write off conscience as a natural phenomenon, an evolutionary instinct. Our inclination to do what is right, they say, exists in order to keep the peace among the human species. The compulsion to do good is required in order to have a society where survival and reproduction are optimized.

But conscience is different from instinct. Though, for example, we have the instinct to preserve our life, the conscience of a firefighter will call her to overrule that instinct and rush into a burning building. Likewise, the conscience of a soldier will call him to rush into the line of fire to rescue an injured comrade. The moral choice may be evolutionarily undesirable, but in such cases, conscience calls for us to overrule this instinct. Furthermore, even in cases where there may be natural advantages to following our conscience, this does not make God’s role obsolete. As philosopher Mitch Stokes reflects:

I have no doubt that our moral code(s) provide survival advantage over many of the alternatives. But this biological benefit does not in itself imply that our ethics developed naturalistically. It may be, for example, that a divine Lawgiver hardwired us with knowledge of moral laws, and one of the benefits of following them is that things will generally go better for us, as well as for others.

So the naturally advantageous results of following our conscience may be the result of God’s genius and careful planning.

It might be tempting to reach for Ockham’s razor at this point. Perhaps this just sounds like we’re superfluously adding God into the picture.  But that’s not the case at all. The unique and unbending authority of conscience must come from somewhere, and as we have noted, there is good reason to believe a personal agent is behind it all. But the only kind of personal agent that could have such absolute authority over humanity is a divine lawgiver; so from this it’s reasonable to conclude that the authoritative personal lawgiver behind the irrepressible “law written on our hearts” is God (Rom. 2:15).