Conscience is a hypothesized ability or faculty that distinguishes whether our actions are right or wrong. In plain English, it is a person's inner sense of what is right or what is wrong morally. It leads to feelings of remorse when we do things that go against our moral values, and to feelings of rectitude or integrity when our actions conform to our moral values. It is also the attitude which informs our moral judgment before performing any action. The extent to which such moral judgments are based in reason has been a matter of controversy almost throughout the history of Western philosophy.
Commonly used metaphors refer to the "voice of conscience" or "voice within."
Views of conscience are not mutually exclusive. Although there is no generally accepted definition of what conscience is or what its role in ethical decision-making is, there are three main factors that determine which stance is adopted.
According to some religious perspectives, your conscience is what bothers you when you do evil to your neighbour, or which informs you of the rightness or wrongness of an action before committing it. Doing good to your neighbor does not arouse the voice of conscience, but wickedness inflicted upon the innocent is sure to make the conscience scream. This is because in these world views, God has commanded all men to "love their neighbor". Insofar as a man fails to do this, he breaks God's law and thus his conscience bothers him until he confesses his sin to God and repents of that sin, clearing his conscience. If one persists in an evil way of life for a long period of time, it is referred to as having one's conscience seared with a hot iron. Many people believe that the conscience is the Holy Spirit.
Many churches consider following one's conscience to be as important as, or even more important than, obeying human authority. This can sometimes lead to moral quandaries: "Do I obey my church/military/political leader, or do I follow my own sense of right and wrong?" Most churches and religious groups hold the moral teachings of their sacred texts as the highest authority in any situation. This dilemma is akin to Antigone's defiance of King Creon's order, appealing to the "unwritten law" and to a "longer allegiance to the dead than to the living"; it can also be compared to the trial of Nazi war criminal Adolf Eichmann, in which he claimed that he had followed Kantian philosophy by simply "doing his job" instead of entering a state of civil disobedience .
In popular culture, the conscience is often illustrated as an angel standing on a person's right shoulder, the good side; on the left shoulder stands a devil. These entities will then 'speak out' to you and try to influence you to make a good choice or bad choice depending on the situation.
In current Catholic teaching, "Man has the right to act according to his conscience and in freedom so as personally to make moral decisions. He must not be forced to act contrary to his conscience. Nor must he be prevented from acting according to his conscience, especially in religious matters" (ibid., paragraph 1782). In certain situations involving individual personal decisions that are incompatible with church law, some pastors rely on the use of the internal forum solution. However, the Catholic Church has warned that "rejection of the Church's authority and her teaching...can be at the source of errors in judgment in moral conduct" (ibid., paragraph 1792)
Modern day scientists in the fields of ethology, neuroscience and evolutionary psychology seek to explain conscience as a function of the brain that evolved to facilitate reciprocal altruism within societies .
Numerous case studies of brain damage have shown that damage to specific areas of the brain (e.g. the anterior prefrontal cortex) results in the reduction or elimination of inhibitions, with a corresponding radical change in behaviour patterns. When the damage occurs to adults, they may still be able to perform moral reasoning; but when it occurs to children, they may never develop that ability.
Behavior destructive to a person's society (either to its structures, or to the persons it comprises) is bad or "evil." Evil or wrong acts provoke either fear or disgust/contempt. Thus, one who threatens people with a chainsaw and one whose sexual practices we ourselves find revolting might both be labeled "bad."
Conscience is what we call those drives that prompt us to avoid provoking fear or contempt in others. We experience the operation of conscience as guilt and shame. We feel guilt when we perceive that others might rightly fear us, and shame when we perceive that others might rightly find us disgusting or contemptible. To avoid these negative and unpleasant feelings, we modify our behavior: thus "conscience" prompts us to behave "rightly."
Guilt and shame differ from society to society, and person to person. This both in the content of what acts might provoke these feelings, and the general degree of how strongly these feelings are felt. Indeed, an individual can feel guilt or shame retrospectively for past acts, as one's ideas about right behavior change. A person's circumstances will also alter their ideas of what is "bad." Persons in nations, religious groups, gangs, or other types of groups will - if their group and another are engaged in physical conflict - view members of the other group as "bad," and view members of that gang harming members of their own as wrong acts.
A requirement of conscience, then, is the capacity to see ourselves from the point of view of another person. Persons unable to do this (psychopaths, sociopaths, narcissists) therefore often act in ways which are "evil."
Another requirement is that we see ourselves and some "other" as being in a social relationship. Persons trying to resolve conflict between groups try (and sometimes succeed) to create a feeling that a social relationship exists, that the groups in conflict all belong to some larger encompassing group. Thus, nationalism is invoked to quell tribal conflict, and the notion of a Brotherhood of Man is invoked to quell national conflicts. There are even appeals to relationships between ourselves and the animals in society (pets, working animals, even animals grown for food), or between ourselves and nature as a whole. The goal is that once people perceive a social relationship, their conscience will begin to operate with respect to that former "other", and they will change their actions.
Conscience, then, and ideas of right and wrong, are a result of the kind of animals we are. We even see this in nonhuman animals .
As science means knowledge, conscience etymologically means with-knowledge. But the English word implies a moral standard of action in the mind as well as a consciousness of our own actions. Conscience is the reason, employed about questions of right and wrong, and accompanied with the sentiments of approbation and condemnation. Any consideration of conscience must consider the estimate or determination of conscience and the resulting conviction or right or duty. For further and wider view of knowing the philosophical view of conscience one must know the prominent ethical philosophers particularly (Socrates,Plato and Aristotle)and 1. Aquinas 2. Kant 3. Confucius 4. Buddhism 5. and then also the entire school of thoughts of Philosophy that deals on Moral issue like the Utilitarian, Pragmaticism, etc.
For Aquinas, our God-given reason, by synderesis, has an innate awareness of good and evil that cannot be mistaken - we all have this ability to distinguish from good and evil in the same quantity, and feel a moral obligation to avoid evil and pursue goodness. Aquinas also described synderesis as an awareness of the five primary precepts as proposed in his theory of Natural Law.
Aquinas referred to the conscience as the conscientia and defined it as the acting out of the information given by synderesis, or the process of judgment which acts upon synderesis - the "application of knowledge to activity."
Aquinas also discussed the virtue of prudence to explain why some people appear to be less 'morally enlightened' than others. Prudence is the most important of all virtues, as it helps us balance our own needs with those of others and to reason out the knowledge of synderesis. Our conscience may be mistaken if we haven't acquired enough of the virtue of prudence, which can lead to a breakdown of communication between synderesis and conscientia.
To clarify things, take the analogy of a locked safe. The safe itself is the moral knowledge of synderesis, the key to the safe of moral knowledge is the virtue of prudence, and the hands of practical application apply the key to unlock the safe is the conscientia.
Aquinas reasoned that acting contrary to your conscience is an evil action, since although it may be mistaken at times it is our only guide. The 'erring conscience' as Aquinas termed it, explains the differences that may arise in different people's conscientia. You have an erring conscience if you are mistaken or confused about the moral course of action. The question could be raised however: is an erring conscience blameworthy? For Aquinas, an erring conscience is only blameworthy if it is the result of culpable or vincible ignorance of factors that are within one's duty to have knowledge of. If however, an erring conscience is the result of an invincible ignorance of factors that are beyond your control, your actions are not culpable. One must also be aware of Aquinas’ distinction between real and apparent goods. Although real goods are from God, apparent goods (when we follow the wrong path believing it to be a real good) are not. An erring conscience may lead us down the path of an apparent good, which will not lead to human flourishing.
Aquinas reasoned that we should educate our consciences in order to act well and align our actions towards the highest good. Although conscience should be applied before an action, it may also retrospectively cause feelings of guilt or satisfaction.
He stated that conscience is a common, one for all, knowledge about what good is and what evil is for humankind. Not for a man, not for his time, not for a group of men, but for humankind as a whole. As language, conscience is individual in each person and it is common for all.
He explained that the truth-conscience enters the man not with genes and not by upbringing: if conscience depended on upbringing then many people would not have known about it at all. It enters the man with a bearer of the common knowledge of good and evil, of the truth - with a common thing - human language. To his opinion, the answer about human conscience is as follows: a man obtains the moral law, which is conscience, through his native language. His consciousness, his self-consciousness, and his soul are forming during the obtaining of speech, his consciousness and his speech - are practically the same thing. In speech and in the language all major images of good and evil, the concept of the truth as well as a concept of the law is available; these concepts and images are becoming a child's own consciousness similar to language. Studying language, its lively phrases, its proverbs, perceiving the folklore, art and literature of his nation, a child is absorbing a common message of good and evil, - his conscience - and besides, he does not notice that, it seems to him that conscience occurred somehow by itself.
Soloveychik wrote, "A child sinking in a moral atmosphere of language and culture absorbs drops of the ocean of public consciousness. Genius people by their immense life work raises to such highs of the truth, that these great people are called the conscience of humankind. But both a two year old child, who feels something similar to a sense of guilt for the first time, and a well-known writer, who is called a guardian of human conscience, drink from the same source of common human knowledge of the truth." .
Related to this idea is the idea of world consciousness. It too, looks at people in terms of the collective, but refers more to the universal ideas of the cosmos, instead of the interconnectedness of choice. In other words, conscience is 'inner voice'.