Aquinas - Vincible and Invincible Ignorance

Key Terms:

Phronesis: A practical wisdom, particularly in relation to moral decisions

Vincible Ignorance: A lack of knowledge for which a person is responsible

Invincible Ignorance: A lack of knowledge for which a person is not responsible

In other theological views where God speaks to us or gives an infallible intuition, it is difficult to see how conscience could be mistaken.

Aquinas, however, allows for this possibility. The errors of conscience can be explained by our ignorance.

Aquinas, conscience is more intellectual and rational.

God does not speak to us through conscience; rather he has given us the tools to work out what we ought to do.

Aquinas - conscience making mistakes

Conscience can make mistakes in a number of ways. It may be that we do not properly develop or educate our conscience yet we may also have difficulties in the 'conscientia - the actual application of moral rules. For example, we may know that it is wrong to steal but not think that copying a CD is an example of stealing. Aquinas believes that we develop our conscience as we gain more experience of reasoning and applying moral rules; hopefully we develop our phonesis or prudence so that we make fewer errors. In terms of the errors that we make Aquinas categorises them as showing either vincible ignorance or invincible ignorance. He uses an unusual and implausible example to illustrate his point:

Vincible ignorance involves a lack of knowledge for which the person is responsible. If a man sleeps with someone other than his wife because he is unaware of the moral rule about adultery or thinks that it does not apply in his case, he is responsible for his error. He ought to know the rule and not pursue an apparent good.

Invincible ignorance involves a lack of knowledge for which the person is not responsible. If a man knowing that adultery is wrong sleeps with a woman believing her to be his wife (and she believes him to be her husband!) then there is no wrongdoing, it is a genuine if unlikely mistake.

The authority of conscience

Whether our conscience is right or wrong, it is effectively all we have in the moment of decision, so Aquinas argues that we are obliged to follow our conscience. It carries authority even on the occasions that it is wrong.

Going further: An alternative theological view of conscience

An alternative theological view of the conscience is found in the writings of J.H. Newman (1801-1890). Unlike Aquinas, Newman's view of the conscience is more of an immediate inner voice rather than our own reasoning. Newman starts with our experience of conscience; he argues that it is a key part of our psychology in the same way as memory and imagination might be. Conscience is effectively God's voice speaking to us directly. It is authoritative and we ought to obey it. We experience guilt and shame when we disobey it.