I was in Skinners’ Hall in the City of London to say Grace for the Worshipful Company of Fuellers and sitting next to the Clerk to the Worshipful Company of Distillers, He asked me, “Have you ever had any doubts about the existence of God?”

Well, yes. There was a time when I was in the first flush of teenage omniscience, round about 1958, when for a few weeks after the end of the cricket season I actually declared myself an atheist. These religious hot flushes can’t last. And, prompted by my first look at Rene Descartes, I soon returned to my senses. It was the “I think, therefore I am” bit. I read it and I thought, “You arrogant bugger!”

And it struck me: how could he think his own existence more certain than the existence of God?

A few years later I read Wittgenstein’s Philosophical Investigations – paragraphs 245-315 in which he demonstrates the impossibility of a private language. How could I ever know that I was using my private language correctly? Memory is only unreliable, and relying on it as a check would be, said Wittgenstein, “…like buying two copies of the morning paper to see if what said was true.” The Cogito is a tautology which merely repeats in the predicate what it articulates in its subject. The fact that I speak a language shows that there must be other speakers from whom I learnt it. In truth, I use the word “I” to distinguish myself from these others.

Years later I read C.H. Sisson’s wonderful remark: “The only word that gives any difficulty in the Creed is ‘I’.”

Descartes (1596-1650) effected a sort of Copernican revolution in which the theocentric metaphysics of the Middle Ages was replaced by the anthropocentric epistemology of the Renaissance.

It was all downhill from then on. Once man puts himself at the privileged centre, he begins to think more highly of himself than he ought to think. Catastrophically, he thinks he can make up morality on the hoof. Deontological ethics – God’s commandments – go out of the window and are replaced by a relativistic utilitarianism in which nothing is good in itself but only in consideration of its consequences.

Jam tomorrow. The notion of the good forever postponed, like a whole series of penultimate climaxes in a Rossini overture.

In the 21st century we have reached the extremes of Cartesian self-centredness in which everyone, however unintelligent and unschooled “has a right to their (sic) own opinion. And, of course, every opinion is to be regarded as as valid as every other opinion. Our technology reflects this mood. Solipsistic babble on the i-phone. Selfies. The dissemination of pictures of one’s private parts in case, pace Descartes, there is anyone out there who might have even the vaguest interest in such pictures.

In short, atheism institutes narcissism. The creation story is reversed and man creates god in his own image – which image is himself.