Have you noticed how the conventional language of morality is slowly disappearing from public discourse? Nowadays, actions are rarely judged to be "right" or "wrong", "good" or "bad". Instead, they are described as "appropriate" or "inappropriate", "positive" or "negative". These euphemisms are now widely employed in schools.
The same trend can be seen in relation to "truth" and "lies". Public figures caught out committing some misdemeanour are rarely accused of lying: rather, they are described as having shown an "error of judgment". We do not subsequently hear calls for greater "honesty". What is usually recommended is that systems - not people - should ensure greater "transparency".
How is this trend to be interpreted? It would be easy to develop a fundamentalist thesis: the loss of confidence in the use of ethical language is part of a general deterioration in public morality. This might be linked to the decline of religion, the growth of individualism and the ascendancy of purveyors of "spin". In turn, it has implications for authority figures, such as teachers and police officers - making their jobs more difficult as the basis of their authority is no longer taken for granted.
A less clear-cut interpretation might suggest that the retreat from absolutist statements is a sign of growing moral sophistication, which recognises the complexity of human behaviour. On this analysis, we are all capable of acting selfishly, unfairly or hypocritically; so we should be cautious about pronouncing dogmatically on the failings of others. Moreover, experience teaches us that the personal histories which cause people to act in particular ways may be painful and difficult. Understanding the causes may be more important than expressing disapproval.
But this more tolerant approach can be taken too far and, in the case of young children, may even be damaging. The work of Piaget and Kohlberg suggests that children pass through various stages of moral development, learning to understand and interpret moral "rules" in the light of growing social experience within the family, the school and the wider community. However, this process depends on the rules being stated clearly in the first place, a requirement that is consistent with the common-sense view of many teachers and parents that firm boundaries should be established about what is acceptable and unacceptable behaviour.
I would have no qualms about saying to older pupils that plagiarism is a form of cheating. Of course, the basic judgment would then have to be supplemented with an explanation of legitimate forms of citation and quotation. Regrettably, many adults seem unaware of these distinctions.
Our politicians set us a very bad example in this area. MPs in the House of Commons are not allowed to accuse each other of lying, even if there is incontrovertible evidence that "porkies" have been uttered. The reason? "Honourable" members are assumed to be incapable of anything so base as falsehood. Aye, right ...
Walter Humes is research professor in education at the University of the West of Scotland.