At the age of nine or 10, when being prepared for the sacrament of Confirmation, I was required to memorise, on pain of being slapped, that the conditions necessary for a mortal sin to be committed were “grave matter, full knowledge and full consent”.
Full consent was explained as acting of one’s own volition and not under threat or duress. This implied that in the absence of duress, a person consciously chose to commit a sin and was therefore entirely culpable for it.
The answer to the catechism question: “What are the effects of original sin?” was: “As a result of original sin our intellects are darkened, our wills are weakened and our passions incline us to evil.”
This suggested that our will might not be entirely free, because the depraved appetite of our First Parents for apples made us more likely to sin.
It had been accepted since the 19th century that much human behaviour, like the behaviour of other mammals, is determined by hormonal balance, genetics and the myriad experiences to which our bodies and minds are subjected.
In his masterly synthesis of research on human behaviour, Behave (2017), Robert Sapolsky argues that there is overwhelming evidence that free will is an illusion because if everything about our genetics, hormonal balance and the experiences we have had, were known, it could be predicted what we would do in any situation.
Righteous behaviour
This determinism in the behavioural sciences is reminiscent of Calvin’s theology of predestination which posits that God has ordained who will be lost and who will be saved and that we can tell who will be saved by their righteous behaviour (and economic success) in this world.
While Calvin's doctrine of predestination calls to mind Karl Marx's comment that theology offers as explanation that which needs to be explained, it has not been an obstacle to it becoming the founding belief of a major Christian denomination.
Calvin's theology of predestination posits that God has ordained who will be lost and who will be saved
The research so eloquently summarised by Sapolsky poses a very serious challenge to Christian teachings on sin and redemption and to the administration of justice. If as Sapolsky points out, brain scans show our brains “deciding” on an action several seconds before we are conscious of deciding, our actions are not consciously “willed” and therefore we cannot be truly responsible for them.
The greatest “sins” are often committed by people who used to be called psychopaths but today are said to suffer from a severe and dangerous personality disorder. The brains of these unfortunate people have weak connections between the pre-frontal cortex which governs feelings of empathy and guilt and the amygdala which mediates fear and anxiety.
Sense of guilt
Because of this, they are likely to commit hideously violent acts for the slightest or no provocation and feel no guilt afterwards. They are not mentally ill in that they understand what they do. But are they guilty in the usual sense of the word if their brains are wrongly structured?
Severe childhood neglect and abuse also damage mental functioning and may lead to reduced feelings of empathy and guilt.
When people believe they do not have free will, they are more likely to act unethically
Sapolsky partially contradicts his argument that all human behaviour is determined by conceding that emotion and reason always interact and that we can modify the fear and prejudices produced by our amygdala, by reflection.
But if his main argument is true, we cannot consciously decide to do this. Sapolsky disarmingly concedes that while he considers free will to be an illusion, he cannot live without this illusion.
That belief in free will is a vital illusion was demonstrated in an experiment by Vohs and Schooler (Psychological Science 2008) which showed that when people believed that they did not have free will, they were more likely to act unethically.
When my daughter was seven or eight, she asked me why God had made the “bad people”. She had discovered one of the main arguments against the existence of a loving God, with which theologians have struggled for two millennia.
I referred her question to an eminent moral theologian who blandly informed her that “the bad people make themselves”. His answer suggests that he believes that all evil actions are freely and deliberately willed.
I sent him a copy of Behave which may cause him to revise this view.
Seán Byrne is a lecturer emeritus in economics at the Technological University Dublin