We have just seen that the word ‘constraints’ may well sound restrictive, as indeed it is when constraints mark the boundaries of the possible or the permissible. But constraints, even when doing that, can also open the way to far greater freedoms of action: those who stop at the fence on the edge of a cliff are more likely to survive and do other things than those who try to walk on air.

Constraints can thus be the necessary condition of freedom, not its contradiction. In the case of human thought and behaviour, they act as markers that guide or control people into their characteristic ways of thinking, speaking and acting. Some (for example, the so-called ‘laws of nature’) are external and are simply the context in which people live. But many are internalised by individuals and become a part of their memory and experience in ways that characterise who they are, what they think and how they behave.

Constraints of that kind are extremely diverse and come (sometimes but not always consciously) from many sources, ranging from family to education, from peer-group approval to manuals and media. In the case of religions, the constraints are many and diverse, but some of the most important are derived from texts or from teachers that are believed to have authority.