There will be few readers who have not heard the story of the Jesuit and the Benedictine who agreed to ask their superiors if they could smoke while praying their Office. The Benedictine asked if he could smoke while he prayed, and got a flea in his ear. The Jesuit asked if he could pray while he smoked, and got congratulated for his piety. But do we often think about the significance of the story?

What it reminds us is that we do not think in a vacuum, because our answers are influenced by what is already in our mind – or in the case of this story what someone has put into our mind. We do not make our decisions from scratch but by comparison. A recent Horizon programme on illusions illustrated how our five senses convey what we expect to happen rather than what actually happens. It’s an essential shortcut in our brains.

J Pierpont Morgan, the great financier, once said: “A man generally has two reasons for doing a thing. One that sounds good, and a real one.” It seemed cynical until, in a few dangerous moments of honesty, I realised how often it happened to me. It runs from the trivial “I’m sorry but I just can’t make it that day” instead of “I don’t want to come because your conversation bores me”, to the more serious “I’m a bit short this month so I can’t lend it to you” instead of “I don’t trust you to pay me back.”

When did you learn to smile? Perhaps it was originally instinctive, or imitated from an adult, but you quickly learnt that a smiling baby got more approval and attention. Today you will often smile, not because you’re happy, but because your brain knows it will create a better atmosphere, and make your requests more acceptable. No doubt you learnt “please” and “thank you” at your mother’s knee, but how often does your “please” consciously mean “if you please”?

Of course you never tell a lie – unless it comes into your private list of white lies. These are naturally well motivated, and often necessary to avoid giving information to the wrong person. Unfortunately the Catechism disagrees: you may never tell a lie of any kind since it breaches God’s purpose for communication. However, you can use “discreet language” in certain cases. I think this simply means that you may deceive – providing you avoid an actual lie. The result would appear to be much the same. Deriving natural law from human structures and so creating absolutes is a dangerous game.

We all have an armoury of deceit which we use almost unconsciously in order to influence the understanding of others. But how about the attitudes we import from others? Perhaps the broadest source is the effect of culture on our conclusions. We don’t have to be very old to recall how much our culture has changed. This is summed up for me by the chief prosecutor’s question at the Lady Chatterley’s Lover trial in 1960. He asked the jury if it were the kind of book “you would wish your wife or servants to read”. The question was a generation out of date even then, and the broad changes of attitude towards sexual practices over 50 years are manifest. I talk to my adult grandchildren about this, and they do not appear to understand my drift.

​How to continue reading…

This article appears in the Catholic Herald magazine - to read it in full subscribe to our digital edition from just 30p a week

The Catholic Herald is your essential weekly guide to the Catholic world; latest news, incisive opinion, expert analysis and spiritual reflection