What religious people mean by “god” means nothing to me beyond an incoherent cluster of concepts from which the aforesaid folk choose the subset most convenient to themselves.

But the word brings to mind the man-made phenomenon of religions, whose net effect on humanity now as throughout history has been, by a considerable margin, negative. It would be so just because of the falsity of belief; and the consequent absurdity of behaviour premised on the idea that there exist supernatural agencies who made this very imperfect world, and who have an interest in us that extends to our sex lives and what we should and should not eat on certain days, or wear, and so on. But it is worse than false: it is far too often oppressive and distorting as regards human nature, and divisive as regards human communities.

It is a frequent source of conflict and cruelty. Monstrous crimes have been committed in its name. And more often than not it has stood in the way of efforts at human liberation and progress.

Apologists for religion point to the Sistine Chapel and Bach’s Mass in B minor as some sort of justification for it. I answer: first, the church had the money to commission these things; second, lots of wonderful art is about naked women and bowls of fruit, and required no belief in deities to prompt its production; and third, the existence of religious art does not excuse burning people alive at the stake for disagreeing with some doctrine or other.

Apologists for religion point to charitable works as some sort of justification for it. I answer: non-believers perform these, too, out of simple fellow feeling, not requiring the idea of pleasing a deity or getting into heaven to prompt them to it.

Apologists point to Stalinism and Nazism as murderous ideologies, as if their existence made Torquemada and the Taliban somehow acceptable. I answer: all monolithic ideologies, claiming to possess the One Great Truth and demanding that everyone to submit to it on pain of penalty, with their prophets and pieties and shibboleths and sacred cows, come to the same thing when allowed to go to their all too natural extremes – which is precisely my objection to religion. This does not stop me having the same objection to Stalinism and Nazism, which I very much do.

The basic doctrines of the major religions have their roots in the superstitions and fancies of illiterate peasants living several thousand years ago. It is astonishing that these superstitions, in the partial guise of sophistical successor versions, retain any credibility. The reason they do is proselytisation of the very young, the institutionalisation of religious sects, and certain psychological factors.

I would wish people to live without superstition, to govern their lives with reason, and to conduct their relationships on reflective principles about what we owe one another as fellow voyagers through the human predicament – with kindness and generosity wherever possible, and justice always. None of this requires religion or the empty name of “god”. Indeed, once this detritus of our ignorant past has been cleared away, we might see more clearly the nature of good, and pursue it aright at last.

A C Grayling is professor of philosophy at Birkbeck College, University of London