Do Christians have the right to wear crosses in public, especially in the workplace? Should Jewish men be allowed to wear yarmulkes and Muslim women burkas? Opinions differ. One side appeals to the freedom of religion. The other appeals to freedom from religion. But why is the issue so provocative?
A symbol stands for something else. Taking something symbolically is the opposite of taking it literally, or as itself. In religion, not only dress but also figures and events are interpreted literally or symbolically.
Often there is disagreement even within a religion. Literally, God in the Bible looks and acts like a human being. God sees, hears, smells, gets upset and rests. God is male and even has sons (Genesis VI, 2-4). Or are these characteristics simply popular ways of describing a God who in reality may not even have a body? When God, in the first of the two creation stories (Genesis I, 1-2.4a), creates male and female humans in the "image" of God, does image refer to sexuality or, more sublimely, to conscience? Views differ among Jews and Christians.
Did the biblical God, in the first creation story, really create the world in just six days, or is "day" symbolic for "aeon"? Did the same God, in the second creation story (Genesis 2.4b-3.24), really create Adam and Eve as the first couple and place them in a magical paradise, where they sinned by eating from the forbidden Tree of Knowledge? Or do Adam and Eve symbolise the innocence of all humans, who "fall" when they become conscious of their sexuality?
Jews interpret circumcision literally, but Saint Paul interprets it symbolically: "For he is not a true Jew who is one outwardly, nor is true circumcision something external and physical. He is a Jew who is one inwardly, and real circumcision is a matter of the heart, spiritual and not literal" (Romans II, 28-29).
Roman Catholics believe that in the Mass bread and wine are literally transformed into the body and blood of Christ. Most Protestants maintain that in the Eucharist bread and wine are only symbolically transformed. This divide is not only academic: it was central to religious wars - wars to the death.
Calling dress a religious symbol is perhaps imprecise. Wearing a yarmulke expresses deference to God, but does not symbolise anything specific. The six-pointed Star of David represents Jewishness generally, which need not be religious.
At the same time, practices that have nothing to do with symbolism also stir outrage. The Jewish observance of dietary laws, or kashrut, traditionally requires the killing of animals in a manner that to some is cruel. The refusal of the Roman Catholic Church to ordain female priests and of the Anglican Communion to ordain female bishops continues to be controversial, to put it mildly. No issue is more heated than that of abortion.
But why is dress, seemingly so innocuous, so controversial? The answer, I think, is the public nature of it. Dressing as one wishes with one's family or in one's neighbourhood is rarely the object of controversy. Parading one's religion in public is.
One of the key characteristics of modernity is the separation of the public domain from the private. Politics is considered public, religion private. Previously, there was barely a separation between the domains. When the Roman emperor Constantine converted from paganism to Christianity in AD312, the state automatically converted with him. In Europe and Scandinavia there have been, and often still are, state churches. The king or queen of England is simultaneously the head of the Church of England, and the coronation is a religious ceremony.
In the US there has never been a state church. But even in countries where state churches remain there has long been religious freedom. A consequence of the differentiation between public and private is that non-Christians can be citizens, can vote, can hold office and can enter any profession.
The House of Lords, a political body, guarantees seats to a slew of Anglican bishops who ostentatiously display their own emperor's new clothes. What, then, is objectionable about the same, often more modest parading of symbols by religious minorities at work and in public? An answer is that religious tolerance for minorities really means sufferance. One is free to tout one's religion or culture as fully as one wants, but only in private, which, to be sure, does not mean in secret. Adherence to Sharia law in the UK or the US is opposed on the grounds that it constitutes the importation of the private sphere into the public.
The two qualities that most conspicuously evince acceptance of one's nationality are language and dress. Not speaking English in the UK or, even more, in the US, is taken as the rejection of one's country. Not dressing like others is taken as the same.
I might seem to be missing the point. After all, Christians, who belong to the majority, are under siege, and not merely Jews, Muslims and Sikhs. But might the answer still be the same? If the public domain is deemed separate from the private one, might religion of any kind have no place in it? Those who say yes would argue that the wearing of even a tiny cross effaces the divide.
Classes in religious education might want to debate this question, which, put another way, asks: does professing one's religion publicly commit a category mistake?
Robert A. Segal is the sixth-century chair in religious studies at the University of Aberdeen. He is the author of Myth: A Very Short Introduction and the editor of The Blackwell Companion to the Study of Religion.
Key stage 1: Sacred symbols
Khat has shared a scheme of work that introduces pupils to the signs and symbols of different religions.
Key stage 2: Symbols of our world
Try a Teachers TV video exploring symbols in Christianity, Judaism, Hinduism and everyday life.
Key stage 3: Symbols of identity
Citizenship Foundation has shared a lesson about the meaning symbols have to individuals.
Key stage 4: Secular exclusion
"A secular society should not prevent people practising their religious beliefs." Pupils debate this statement in a lesson from instituteofideas.
Key stage 5: Burka ban
Cecr asks students whether the burka should be banned, in a post-16 RE lesson.