Aquinas argued that people have the God-given the ability to reason (an idea inspired by Aristotle) and that reason will lead to knowledge of synderesis (an awareness of the five primary precepts presented in Aquinas’ Natural Law argument). For Aquinas, conscience is the “dictate of reason.”

Synderesis is a God-given innate awareness of good and bad that cannot be mistaken. We should follow synderesis rule – avoid evil and follow good.

Our conscience or “conscientia” is acting out the information given by synderesis or a process of judgment which acts upon synderesis:

“The application of knowledge to activity”

It is an evil action not to follow our conscience. Even if our conscience is wrong, it is our best guide – “conscience is blinding.”

Prudence is a virtue that must be acquired which helps us to balance our own needs with those of others. For Aquinas it is the most important virtue, and allows us to reason out the knowledge of synderesis.


Conscience may be mistaken if we haven’t acquired enough of the virtue of prudence as this will lead to a breakdown in communication between synderesis and conscientia.

The following analogy can be used to explain the relationship between synderesis, prudence and conscience:

i Safe of moral knowledge = Synderesis
i Key to the safe of moral knowledge = Prudence
i Hands of practical application = Conscience

(not Aquinas’ analogy)

You are said to have an erring conscience if you are unsure and mistaken about the moral course of action. In such a case you may pursue an apparent good rather than a real good, which does not lead to human flourishing.

According to Aquinas, an erring conscience is only blame worthy when it is derived from vincible ignorance.

Two types of ignorance:
1. INVINCIBLE IGNORANCE – Non-culpable ignorance, factors that are beyond your control
2. VINCIBLE IGNORANCE – Culpable ignorance, factors within the realms of your duty to be knowledgeable of

For Aquinas, Conscience should be applied before an action. It can however be backwoods looking when we get feelings of ‘reatus’ (guilt) or satisfaction.

Aquinas argued that we should educate our consciences in order to bring ourselves in line with the church.


Joseph Butler was the Bishop of Durham, an Anglican and theologian

For Butler there are two basic principles of human influence:

(1) Self love
(2) Benevolence

Conscience is the balancing force of these two influences
It directs us towards the interests of others and away from ourselves

Like Aquinas, Butler argued that we have been made in the image of God with the ability to reason. Conscience is based on moral reason - a component of the conscious mind. It is innately God-given, but not the voice of God, but the capacity to act as a moral judge, the final arbiter or the one employed to judge inherent in our being.

Our conscience has outright authority in ethical judgements and does not require any introspection. It gives instant, intuitive judgements and is not considered to have the capacity to be mistaken.

Conscience is a guide to moral behaviour put there by God and must be obeyed. If it instructs you to act in a certain way this is adequate justification to act in this way:

Conscience is “our natural guide, the guide assigned us by the Author of our nature”

Butler maintained that you cannot distinguish between conscience and human nature, since conscience is a part of human nature. You are not acting in a human way if you are not acting according to conscience. In order to be moral one must ‘know thyself.’ If we all knew ourselves conscience would govern the world:

“Had it strength as it had right; had it power, as it has manifest authority, it would absolutely govern the world.”


“I shall drink to the pope if you please – still, to conscience first and to the pope afterwards”
[A speech by Newman at that caused much controversy in the Catholic Church]

Newman’s concept of conscience caused him to reject Protestantism and embrace Catholicism. Newman was concerned about the true authority of the Protestant clergy since it was not a direct result of apostolic succession.

Conscience is…

“… a principle planted within us, before we have had any training, although training and experience are necessary for its strength, growth and due formation.”

1) There must be a planter for conscience to be planted, conscience is God-given
2) Conscience is innate
3) Conscience does need help, support and guidance

Newman argued that many of us are guilty of having a fake conscience – one which has been shaped by society. For Newman, ‘Conscience’ as a concept has been misunderstood and is used to defend personal choice and any type of personal behaviour.

This is what Newman calls a “stern monitor” (a strict observation) that has nothing to do with our own desires and will. In Newman’s words:

“Conscience is the aboriginal vicar of Christ.”

For Newman therefore, Conscience is the literal voice of God.


Freud was a psychologist who believed that conscience is a result of the conditioning of a growing being. He argued that the human psyche or mind is split into three parts:

1. ID – basic instincts and primitive desires e.g. hunger, lust etc.
2. EGO – perceptions of the external that makes us aware of the ‘reality principle,’ one’s most outward part and personality
3. SUPER-EGO – the unconscious mind which consists of:
a. The Ego-ideal which praises good actions
b. The conscience which makes you feel guilty for bad actions

For Freud, conscience cannot be the voice of God because of the differing opinions on ethical issues; it is the super-ego of the mind, a ‘moral policeman’ developed during child hood (the third stage known as the phallic stage between 3 and 6 years old).

Freud reasoned that everyone aims to please and be rewarded by authoritative figures, and this is the reason for the social creation of the conscience. He argued that in order for the psyche to be healthy there must be a balance between with the ego and the super-ego. He said that religious belief was an “adolescent stage in the development of the human race from which humanity should free itself.”  For Freud, the Christian conscience is bad for a person’s mental health because of the rules and taboos it imposes.

Freud’s concept of the conscience is thus psycho-analytical; a component of the unconscious mind. Since Freud, other psychologists have developed an understanding of the ego as a mature and healthy conscience reflecting on the best way to behave. The super-ego however is an immature and pathological conscience reflecting on guilt learned at a pre-rational age from a demanding parent.


Piaget was a psychologist who focused his work on cognitive development in children. Whilst watching children playing marbles he observed the development of skill and reasoned that morals are a result of cognitive development, which can also be observed through game play.

Piaget observed children playing games in three stages:
1. Playing on their own
2. Playing with others with a sense of absolution and a need for justice to see that punishment is done
3. A more co-operative stage of discussion and compromise

For Piaget, morality is progressive and developmental.

He presented children with two different dilemmas. The first involved a door with 15 cups placed on a chair behind it. A boy named John opens the door not knowing about the cups and they all fall to the floor and smash. A second boy named Henry went into the kitchen cupboard knowing it was wrong and spilt some jam. Piaget observed that children below 10 though that John was naughtier than Henry, hence he reasoned that children under 10 generally only look at the consequences of their actions. After the age of 10 intentions are taken into account.

This is evidence of the cognitive developmental process through which a moral sense is acquired. For Piaget, by the age of 10 a child should have acquired a full moral sense with a fully developed conscience.


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