A Constantine was converted to Christianity (Annals of Ulster, 588). A Constantine appears in the Breviary of Aberdeen as entering a monastery in Ireland incognito before joining Saint Mungo (alias Kentigern) and becoming a missionary to the Picts. He is probably the same man. This Constantine was martyred in Scotland about 576 and John of Fordun tells how he was buried at Govan, where his shrine can still be seen today. He is probably not the Saint Constantine of Devon and Cornwall, and certainly not the King Constantine of Dumnonia (south-western Britain) mentioned unfavourably by the chronicler Gildas. The fact that there were separate tribes of Dumnonii in the south-west and in Scotland merely serves to make things even more interesting. But – at the risk of upsetting historians – the only thing that matters to us is that the Constantine we celebrate today has been revered as a saint continuously for a millennium and a half. When all the facts about us are lost, may we also be worthy to be remembered.

  Jesus (or the scribe) appears to be quoting from the Old Testament, but one phrase does not exist in any text of the Commandments: that we should love the Lord our God with all our mind.

  It is easy not to notice this phrase, and indeed Matthew, Mark and Luke don’t notice it. We know this because normally when Jesus departs from the Old Testament it is noticed, and remarked upon, and made the subject of a whole “But I say to you…” discourse.

  Not here.

  There are two aspects to this. One is what it says about the past, the other is what it says to us. The past is straightforward. The Jews have never been “people of the Book” in the sense of believing in the Bible and nothing but the Bible. They have, it is true, had a peculiar reverence for every sacred word, but they have lived not in unthinking obedience to those words alone but in a dialogue, you might even say in a relationship, with the sacred text. So the fact that “all your mind” appears here, without attracting notice or comment, must mean that it had become a part of the generally accepted interpretation of the words of Scripture. When, centuries after the Pentateuch, the Jews came across the new, Greek ways of thinking – as the Wisdom literature shows that they did – they immediately realised that this new thing called “mind” was included, no doubt about it, in the commandment to love.

  What this says to us is more important than just a footnote in the history of ideas. It is the foundation and justification of all science. God does not command the impossible. If he is to be loved with the mind, that can only be because he is lovable with the mind, or, to detheologize the language, because Ultimate Being can be related to rationally. The Gospel phrase tells us that things make sense and that we have the equipment to make sense of them.

  What does omnipotence mean? Does it mean that the Omnipotent can do anything at all? If that were true, all science would be at an end. If God willed that when I dropped a glass on the floor it would shatter, then even if God had willed the same whenever anyone in the past had ever dropped a glass, that would still not bind God. God would still be free to decide, if I dropped a glass on the floor now, that this particular glass, alone among all the glasses in history, should bounce and not break.

  Which is to say: on this interpretation of divine omnipotence, science is impossible. We cannot predict the result of an experiment, because next time God may decide differently. We cannot even lay down laws of nature based on previous experience, because to call a law a “law” is to claim to be able to bind God, which is blasphemy.

  This is not merely an academic quibble. When the 11th-century Muslim philosopher al-Ghazāli propounded this very idea, it captured the mainstream of Islamic thinking and led to the virtual suicide of science in Islam and the abandonment of rational thinking about the physical world, as being unnecessary, or sacrilegious, or both.

  We are saved from this by this one little phrase in the Gospel, about loving God with all our mind. It is more than mere permission, it is a command to understand, to go out and do science, and it was followed whenever Christians had leisure to think. It led to the dazzling 13th-century renaissance and the birth of modern science, and we are still living through its consequences.

  As for divine omnipotence, this is not the place to go into it in detail, but the answer to al-Ghazāli must surely be that God can indeed make the glass bounce, but God cannot make the glass bounce and still be God, since to break the laws and regularities of nature whimsically and without reason would be to abandon lovability-with-the-mind. This is exactly the argument that theologians use against pointless or frivolous miracles, but it applies to science as well, and to the possibility of doing science at all.

  He founded a monastery in Rome and some others in Sicily, then became a monk himself. He was ordained deacon and sent as an envoy to Constantinople, on a mission that lasted five years.

  He was elected Pope on 3 September 590, the first monk to be elected to this office. He reformed the administration of the Church’s estates and devoted the resulting surplus to the assistance of the poor and the ransoming of prisoners. He negotiated treaties with the Lombard tribes who were ravaging northern Italy, and by cultivating good relations with these and other barbarians he was able to keep the Church’s position secure in areas where Roman rule had broken down. His works for the propagation of the faith include the sending of Augustine and his monks as missionaries to England in 596, providing them with continuing advice and support and (in 601) sending reinforcements. He wrote extensively on pastoral care, spirituality, and morals, and designated himself “servant of the servants of God.”